23 New Compounds and Structures P. LIGHTFOOT School of Chemistry University of St Andrews St Andrews Fife KY16 9ST UK 1 Introduction The aim of this review is to present an overview of the developments in new compounds and structures of interest to the solid state chemistry community in 1994. The field is currently too vast to provide a comprehensive treatment in a review of this size. Instead the content has been limited to new inorganic extended lattice structures and concentrates on new structural types. Hence new phases adopting well-known structure types or simple variants of these are not included. Even then the content is necessarily somewhat subjective and the article seeks to give a flavour of the current directions in inorganic solid state chemistry and include the most interesting new structures across the whole field.The particular area of cuprate chemistry relevant to high T materials is not dealt with as this is covered in another chapter. The organization of the review is via periodic classification-transition metal oxides other metal oxides non-metal oxides and non-oxides. 2 Overview Solid state inorganic chemistry is a flourishing field with the search for technologically important materials becoming ever keener. The imagination and skill of the synthetic chemist is becoming more evident in the materials area with new methods based on soft chemistry becoming as prevalent as the traditional high-temperature routes to new materials. It is particularly apparent that the use of hydrothermal and related methods although still little explored and understood will provide a rich source of fascinating new solid state chemistry and potentially useful materials in the future.Additionally the area of composite inorganic-organic frameworks is becoming more widely explored. 3 Transition Metal Oxides First Row Transition Metal Oxides.-A new polymorph of TiO, TiO,(R) having a ramsdellite-like structure has been synthesized by topotactic oxidation of Lie,,TiO in acidic solution.' A soft-chemical route has also been used to prepare a hybrid layer/tunnel intergrowth structure M6+6Ti16035+6,2 (M = K Rb; -0.7 < 6 < 0.5) J. Akimoto Y. Gotoh Y. Oosawa N. Nonose T. Kumagai and K. Aoki J.Solid State Chem. 1994,113,27. T. Sasaki M. Watanabe Y. Fujiki and Y.Khami Chem. Muter. 1994,6 1749. 417 418 P. Lightfoot 0La a Figure 1 The structure ofLa,Ti,A " -5% (Reproduced by permission f;om J. Solid State Chem. 1994 111 52) comprised of layer-type Ti80Lfg units and tunnel-type Ti,O:; units stacked in an alternating manner. The new reduced titanate Ba2Ti,30,23 has been shown to adopt a close-packed structure related to BaTi'O ,,with additional Ti atoms occupying face-sharing octahedral sites giving a short Ti-Ti distance as in the hexagonal perovskite structure. The structure of a complex mixed oxide of Ti La3Ti,Al1503 (Figure l) has been solved ab initio from combined X-ray and neutron-powder diffraction data4 and represents the most complex structure to have been determined this way to date.A new 24-layer oxide Ba8V702 (Figure 2) has been prepared.' It represents the first vanadium oxide in which both VOZ- and VOZ-coordinations and the coexistence and ordering of all three common oxidation states of vanadium (+3 +4 and +5) are observed. Bi1.7V80166 represents the first example of a hollandite-type J. Akimoto Y. Gotoh M. Sohma K. Kawaguchi and Y. Oosawa J. Solid State Chem. 1994 113 384. R.E. Morris J.J. Owen J.K. Stalick and A.K. Cheetham J. Solid State Chern. 1994 111 52. G. Liu and J.E. Greedan J. Solid State Chem. 1994 108 371. F. Abraham and 0.Mentre J. Solid State Chem. 1994 109 127. New Compounds and Structures Figure 2 The structure of Ba,V,O, (Reproduced by permission from J. Solid State Chem.1994 108 371) compound having bismuth in the large tunnels. Bi is coordinated by a very flat square pyramid of oxygen atoms from the V80, framework. A new Mn"' oxide BaMn,O,(OH) has been prepared hydr~thermally.~ The structure consists of ribbons composed of four parallel chains of edge-sharing MnO octahedra. One out of two Mn atoms is missing from the inner chains the corner-sharing oxygens from these chains being replaced by Ba. Several interesting new nickel oxides have been studied. YSr,Ni,O is a stoichiomet- ric oxide of Ni' having a structure related to that of Sr,CuO in which 1/3 of the bridging oxygen atoms are missing from chains of apex-linked Ni-0 square planes. On the contrary the Yb-Sr-Ni-0 system has no K,NiF,-related phases.Instead YbSr,NiO has a structure related to that of K,PtC1,.9 The phase previously reported as Sr,Ni,O, has been shown" to be the mixed valent Sr,Ni,O,. This material adopts ' 0.Tamada H. Paulus H. Fuess N. Yamamoto and S. Muranaka J. Solid State Chem. 1994 108 112. M. James and J.P. Attfield J. Chem. Soc. Chem. Commun. 1994 1185. M. James and J.P. Attfield J. Mater. Chem. 1994 4 575. lo F. Abraham S. Minaud and C. Renard J. Mater. Chem. 1994 4 1763. 420 P. Lightfoot a trigonal structure with three independent face-sharing sites-suggesting partitioned Ni" in octahedral and Ni" in trigonal prismatic coordination. The compound Sr,NiPtO,' also contains trigonal prismatic Ni" in a one-dimensional structure related to that of Sr,PtO,. Stoichiometric BaNi,~,,O,, again shows partitioning of mixed valence Ni.Three octahedral sites in the hexagonal perovskite-related structure are occupied" by Ni" N?" and Ni".Finally Li,Ni,TaO has a novel rock-salt superstructure with Ta ordered and Li/Ni partially ordered over octahedral sites. l3 The Li site disorder is static and does not yield significant Li+ ion conductivity. Cuprates containing discrete planar CuO sheets have continued to be widely studied in relation to superconductivity and are discussed elsewhere in this Volume (in the chapter entitled 'Conducting Solids Covering Ionic and Electronic Conductors'). One example of a related structure is the mixed copper-cobalt phase Eu,~,Ba,~,Co,Cu30 2,14 which adopts a new structure comprising a 1 1 intergrowth of '112' and '1 23' elements.A new three-dimensional oxygen-deficient copper perovskite La,BaYCu,O, (Figure 3) has been ~repared.'~ It is related to the well-known La,BaCu,O, by insertion of extended layer-like '123' areas in the three-dimensional network caused by incorporation of the smaller Y ion. + A new series of magnetic cuprates RCu,O (R = La Nd Sm and Eu) has been reported.' The Cu-0 network consists of a three-dimensional array of corner-shared CuO square planes with a Cu-0-Cu angle of -115".A complex new series of tubular bismuth cuprates has been prepared by Li-doping of (Bi +xSr2 -,CuO +&-(Sr8-,,Cu6016+z). Models have been proposed for various members on the basis of detailed HREM data.17 Heavier Transition Metal Oxides.-A complex mixed oxide of Zr and Nb Li29Zr9Nb3040,has been identified and shown to have a rock-salt-related superstruc- ture18 in which 5% of the oxygen sites are vacant in an ordered manner.Li and Zr/Nb order on the cation sub-lattice with Li adopting four- five- and six-coordination. Several new reduced niobates have been prepared. Nb18P,~,05 is a slightly reduced form of Nb,PO, and is isostructural with it.19 It adopts a block structure with 3 x 3 Re0,-type slabs connected in chains leading to semiconducting behaviour in this direction. Rbl~,,NbloOl (Figure 4) has three discrete Nb sites." The reduced Nb is sited in octahedral [Nb,O,,]O clusters while NbV occurs in both octahedral and tetrahedral sites. A related compound is Rb,A1,Nb3s0,,,21 again having three types of Nb site-octahedral [Nb,O,,]O clusters isolated NbO octahedra and Nb,O clusters of face-sharing octahedra.T.N. Nguyen D. M. Giaquinta and H.-C. zur Loye Chem. Muter. 1994 6 1642. J. A. Campa E. Gutierrez-Puebla M. A. Monge I. Rasines and C. Ruiz-Valero J. Solid State Chem. 1994 108 230. l3 J.G. Fletcher G. C. Mather A. R. West M. Castellanos and M. P. Gutierrez J. Muter. Chem. 1994,4 1303. l4 L. Barbey B. Domenges N. Nguyen and B. Raveau J. Solid State Chem. 1994 111 238. l5 R. J. Cava H. W. Zandbergen R. B. Van Dover J. J. Krajewski T. Siegrist W. F. Peck jr. R. S. Roth and R. J. Felder J. Solid State Chem. 1994 109 345. l6 S.W. Keller V.A. Carlson D. Sandford F. Stenzel A. M. Stacy G.H. Kwei and M. Alario-Franco,J.Am. Chem. Soc. 1994 116 8070. li G. Van Tendeloo B. Domenges M. T. Caldes M. Hervicu and B. Raveau J. Solid State Chem. 1994,112 161. P. Lightfoot J.B. Thomson F. J. Little and P.G. Bruce J. Muter. Chem. 1994 4 167. l9 J. Xu S.C. Chen K. V. Ramanujachary and M. Greeblatt Inorg. Chem. 1994 33 267. " N. Kumada N. Kinomura R. Wang and A. W. Sleight Muter Res. Bull. 1994 29 41. '' M.J. Geselbracht and A.M. Stacy J. Solid State Chem. 1994 110 1. New Compounds and Structures 421 Ba eY La CU06 cuos cuo4 octahedion pyramid square Figure 3 Idealized structure of La,BaYCu,O, (Reproduced by permission from J. Solid State Chern. 1994 109 345) A new reduced Ruddlesden-Popper related phase Rb,LaNb20,,22 has been prepared by a novel soft-chemical route-reaction of RbLaNb207 with Rb vapour at 250°C.The structure of Li,NaTa,O, has been derived from powder diffraction data., It is related to the tetragonal tungsten bronze structure with Ta in octahedra and pentagonal bipyramids and Na occupying the pentagonal channels. Molybdate chemistry has remained a very active area. Two fully oxidized compounds NaY(MoO,) and Na,Y(MoO,), have been shown to have structures related to that of scheelite., The latter phase has Na partially occupying the tetrahedral sites in an ordered arrangement with Mo. The reduced phase (Mo,Nb),,O, has a block structure composed of 3 x 4 blocks interconnected through MOO tetrahedra.25 K,.,,Ba,~,,Mo,,O, (Figure 5) has been shown to be the n = 5 member of the metal-metal bonded oligomer series M,-xM04n+206n+4 containing Mo, clusters consisting of five trans edge-shared Mo octahedra26 with all octahedral edges bridged by 0 atoms.Similarly Ba3Mo,,02,27 represents the n = 4 oligomer. A prominent feature of these structures is the pronounced short-long-short arrangement of apical-apical Mo bond distances. 22 A. R. Armstrong and P. A. Anderson Inory. Chem. 1994 33 4366. 23 J. Grins L. Banos D. C. Sinclair and A. R. West J. Muter. Chem. 1994 4 445. 24 N.J. Stedman A.K. Cheetham and P.D. Battle J. Muter. Chem. 1994 4 707. 25 S.C. Chen and M. Greenblatt J. Solid State Chem. 1994 108 366. 26 G. L. Schimek and R. E. McCarley J. Solid State Chem. 1994 113 345. ’’ G. L. Schimek D.A. Nagaki and R.E. McCarley Znorg. Chem. 1994,33 1259.422 P. Lightfoot Rb Nb06 octahedra Nb04 tetrahedra Figure 4 Crystal structure ofRb,,,,Nb,,O, (Reproduced by permission from Mater. Res. Bull. 1994 29 41) The structures of two new layered molybdates have been derived from powder diffraction data. Mo03.1/2H20 has isolated layers formed by double rows of edge- sharing octahedra linked through corner-sharing octahedra.28 (NMe,)Mo -,O has a different arrangement of the MOO octahedra than any of the known molybdenum oxides.29 Two new tungstates have been prepared and characterized.,’ La,W,O, can be considered a distorted superstructure of scheelite with 1/3 of the A sites vacant. The compound LaFeW,O, (Figure 6) has a layer structure consisting of two distinct layers; the first has WO tetrahedra and La in eight-coordination whereas the second has both Fe and W in edge-sharing octahedra.The subvalent oxide Ag,SiO has been shown to contain both isolated Ag’ ions and Ag clusters suggesting a better formulation as [Ag614+ (Ag+),(SiO:-)2.31 4 Other Oxides Metal Oxides.-Bismuth oxide chemistry has remained active due to its relevance in the high T field. Somewhat surprisingly in this respect new structural details are still being elucidated in the ‘simplest’ systems. Bi,BaO,. has been shown to adopt a perovskite-related structure with Bi and Ba randomly occupying the B sites.32 High ionic conductivity is observed on the anion sub-lattice. CaBi20 has been shown to adopt a sheet structure with four-coordinated Bi polyhedra distorted to accommodate ” P.Benard L. Seguin D. Louer and M. Figlarz J. Solid State Chem. 1994 108 170. ” J. Guo P. Zavalij and M. S. Whittingham Chem. Muter. 1994 6 357. 30 M. Gartner D. Abeln A. Pring M. Wilde and A. Reller J. Solid State Chem. 1994 111 128. 31 C. Linke and M. Jansen Inorg. Chem. 1994,33 2614. 32 C. Michel C. Pelloquin M. Hervieu B. Raveau F. Abbattista and M. Vallino J. Solid State Chem. 1994 109 122. New Compounds and Structures Figure 5 The structure ofK,,,,Ba,,,,Mo,,O, (Reproduced by permission from J. Solid State Chem. 1994 113 345) the lone pair.33 A new oxyhydroxide La0,26Bi0,7400H has been shown to be the first example of a PbFC1-related structure with complete substitution of OH on the C1 site.34 Sb,WO has been reported to be the first pure Sb analogue of the Aurivillius series of bismuth oxides.35 A new gallate Na,Ti,-,Ga,+,0,,,36 has been studied as a potential Na' ion conductor.The structure shows sodium ions residing in one- dimensional tunnels of octagonal cross-section. Phosphates.-Phosphate chemistry continues to be one of the most active areas of exploratory solid state chemistry. Many new structure types have been reported this year synthesized either hydrothermally or by solid-state reaction. Raveau and co-workers have continued to be prominent in the development of transition metal phosphate chemistry by solid-state means. The new reduced titanium phase K0.,8TiP20,37 has been shown to contain corner-linked TiO and P207groups 33 I. Natali Sora W. Wong-Ng Q.Huang R. S. Roth C. J. Rawn B. P. Burton and A. Santoro J. Solid Stute Chem. 1994 109 251. 34 N. Kumada N. Kinomura S. Kodialam and A. W. Sleight Muter. Res. Bull. 1994 29 497. 35 A. Castro P. Millan R. Enjalbert E. Snoeck and J. Galy Muter. Res. Bull. 1994 29 871. 36 Y. Michiue and M. Watanabe Solid Stute lonics 1994 70/71 186. 37 A. Leclaire J. Chardon M. M. Borel and B. Raveau J. Solid Stute Chem. 1994 109 83. 424 P. Lightfoot C Figure 6 Schematic diagram of the structure of LaFeW,O, (Reproduced by permission from J. Solid State Chem. 1994 111 128) forming tunnels; of the two independent K sites one is partially occupied suggesting a possibly wide range ofnon-stoichiometry .Several new vanadium phosphates have also been prepared-Cd,V,(P0,),,38 CdV,0(P0,),,39 Pb2V,VO(P0,),,40 and Cd,VP0,41 contain vanadium in oxidation states 11 111 III-IV and v respectively.Two new niobium phosphates show relationships to well known oxide structures; RbNb,P0842is derived from the hexagonal tungsten bronze structure via an ordered substitution of PO tetrahedra for NbO octahedra whilst Rb3NbsP,0,,43 is related to pyrochlore. The same group have also reported several molybdenum phosphates. Layer structures are obtained for B~Mo,O,(PO,)~,~~ derived from cube-like Mo,O:+ units and KMO,P,O,,,~~ derived from sheets of alternating vertex-linked MOO,and PO polyhedra joined by unusual trigonal bipyramidal MOO groups. Tunnel structures are obtained for R~,O,(MOO),(PO,),,~~ which is derived from the 38 S.Boudin A. Grandin M. M. Borel A. Leclaire and B. Raveau J. Solid State Chem. 1994 110 43. 39 S. Boudin A. Grandin M. M. Borel A. Leclaire and B. Raveau J. Solid State Chem. 1994 111 380. 'O A. Leclaire J. Chardon A. Grandin M. M. Borel and B. Raveau J. Solid State Chem. 1994 108 291. 41 S. Boudin A. Grandin A. Leclaire M. M. Borel and B. Raveau J. Solid State Chem. 1994 111 365. 42 A. Leclaire M. M. Borel A. Grandin and B. Raveau J. Solid State Chem. 1994 110 256. 43 A. Leclaire M. M. Borel J. Chardon and B. Raveau J. Solid State Chem. 1994 111 26. ''M.M. Borel J. Chardon A. Leclaire A. Grandin and B. Raveau J. Solid State Chem. 1994 112 317. 45 A. Guesdon M. M. Borel A. Leclaire A. Grandin and B. Raveau J. Solid State Chem. 1994 109 145. 46 M. M. Borel A.Leclaire A. Guesdon A. Grandin and B. Raveau J. Solid State Chem. 1994 112 15. New Compounds and Structures Figure 7 Portion of the crystal structure of Cs,Mo,O,(PO,),.H,O (Reproduced by permission from J. Solid State Chern. 1994 111 315) previously known K,O(MoO),(PO,) by a 180" rotation of adjacent layers and CS6M070,(P04),.H20,47 which has large 'butterfly-shaped' tunnels from which water can be reversibly de-intercalated. (Figure 7). Other new phosphates prepared by solid-state techniques include CaYP70,0,48 the first characterized n = 5 member of the ultraphosphate series [P,+ ,03*+ J- U(U0,)(P04),49 which has discrete Uv' and U" sites in PaC1,-type chains and P-BaV,(P,O,) having a complex intersecting tunnel structure. O Hydrothermal methods have been used by many groups to prepare new phosphates.Ferey and colleagues have extended their series of oxyfluorinated phosphates to include several new gallium phase^^',^^ as well as materials based on vanadium and iron. Ga16(P04)14(HPO)2(OH),F7.[H,N(CH2)6NH3],.6H,0 has been shown to contain 16-membered ring channels and is the first phase to include both bonding and encapsulated F-(Figure 8). [V,P04F12 -[C2N,H,,]2 53 and Fe3 +Fe2 fF,(HP0,),.ethylenediamine.2H2054 + represent the first reported fluorinated vanadium and iron phosphates respectively. Two further microporous gallium phosphates are Ga3P30,,0H.H3CNH,CH3,55 isotypic with AlP04-21 and Ga3(P0,),F3P.C,Hl,N (Figure 9),56 containing bell-shaped channels of approximate dimensions 7 x 9 A.Reduced and mixed valence 47 A. Guesdon M. M. Borel A. Leclaire A. Grandin and B. Raveau J. Solid State Chem. 1994 111 315. 4R A. Hamady and T. Jouini J. Solid Stute Chem. 1994 111 443. 49 P. Benard D. Louer N. Dacheux V. Brandel and M. Genet Chem. Muter. 1994 6 1049. S.-J. Hwu R.1. Carroll and D. L. Serra J. Solid State Chem. 1994 110 290. 51 T. Loiseau R. Retoux P. Lacorre and G. Ferey J. Solid State Chem. 1994 111 427. 52 T. Loiseau and G. Ferey J. Solid State Chem. 1994 111 403. 53 D. Riou and G. Ferey J. Solid Stute Chem. 1994 111 422. 54 M. Cavallec D. Riou and G. Ferey J. Solid State Chem. 1994 112 441. 55 T. Loiseau D. Riou M. Licheron and G. Ferey J. Solid State Chem. 1994 111 397. '' X. Yin and L.F. Nazar J. Chem. Soc. Chem. Commun.1994 2349. 426 P. Lightfoot Figure 8 Theframework structure of Gal6(P04)14(HP04),(OH),F,.[H,N(CH2),NH3]4.6H,0 (Reproduced by permission from J. Solid State Chem. 1994 111,403) Figure 9 Framework structure ofGa3(P04),F,P.C4H14Nz (Reproduced from J. Chem. SOC. Chem. Commun. 1994 2349) New Compounds and Structures A10 PO 0. Co No Figure 10 Two views of the layer structure o{ (Al,P,O 6)3 -[NH,(CH,),NH,] (C,H oNH2)f + (Reproduced from J. Chem. Soc. Chem. Commun. 1994 565) vanadium phosphates have been further explored. Cs[(V,03)(HP0,),(H,0)] 57 has a one-dimensional (-V'v-O-Vv-O-) chain of corner-sharing octahedra. Two new layered V" compounds have been shown to be based on distorted and defected VOPO layers,58 whilst V,P,O,,(H,O),.H,N(CH,),NH is a mixed valence microporous phase having ten-membered ovoid channels.59 The potassium vanadium phosphates K,(VO)(V,03)(P0,),(HP04)and K3(VO)(HV,0,)(P04),(HP0,) are isostructural and differ only in the addition of an extra hydrogen atom into nearly iden tical frameworks.6o " R.C. Haushalter Z. Wang M. E. Thompson J. Zubieta and C. J. O'Connor J. Solid Stute Chem. 1994 109 259. '' V. Soghomonian R. C. Haushalter Q. Chen and J. Zubieta Inorg. Chem. 1994,33 1700. 59 T. Loiseau and G. Ferey J. Solid State Chem. 1994 111 416. 6o J.T. Vaughey W.T.A. Harrison and A. J. Jacobson J. Solid Stute Chem. 1994 110 305. 428 P. Lightfoot Figure 11 The structure of [C,H,NH] +[CoGa2P,OI2]-(Reproduced from J. Chem. Sac. Chem.Commun. 1994 2453) A new layered aluminophosphate,61 (Al,P4016)3-[NH,(CH2)sNH,]2+ (CsHloNH2)+ has been prepared using 1,5-diaminopentane as the initial template molecule (Figure 10). Cyclization of part of the template to give piperidinium and partioning of the two resultant species into different voids circular and elliptical within the layers is a unique example of a reactive template in hydrothermal synthesis. Two new microporous cobalt-containing phosphates have been reported; COPO,.O.~C~H~~N,~~ is the first reported open framework structure with a 1 1M :P ratio having the transition metal exclusively occupying tetrahedral sites whilst [C,H,NH] +[CoGa,P,O 12] -(Figure 1 1) is the first heteroatom-substituted micro- porous gallium ph~sphate.~~ The zinc phosphate Zn4(P04)3(H20)(C,HsNH,)64 is unusual in having a M :P ratio greater than unity leading to direct Zn-0-Zn linkages.In the search for ever more complex framework structures K[Ni(H,0),A1,(P04),] is the first reported example of an octahedral/trigonal bipyramidal/tetrahedral framework Des-pite the abundance of work on AlPO’s and GaPO’s very little work has been reported 61 R. H. Jones A. M. Chippindale S. Natarajan and J. M. Thomas J. Chem.SOC.,Chem. Commun. 1994,565. 62 J. Chen R. H. Jones S. Natarajan M. B. Hursthouse,andJ. M. Thomas Angew. Chem.,Int. Ed. Engl. 1994 33 639. 63 A.M. Chippindale and R.I. Walton J. Chem. SOC. Chem. Commun. 1994 2453. 64 T. Song M. B. Hursthouse J. Chen J. Xu K. M. A. Malik R. H. Jones R. Xu and J. M.Thomas Adv. Muter. 1994 6 679. 65 L. M. Meyer and R.C. Haushalter Chem. Mater. 1994 6 349. New Compounds and Structures 429 on the heavier B-metal phosphates; Cs[In2(P0,)(HP0,)2(H,0),]66 is one of the few indium phosphates so far characterized. An unusual layered zirconium phosphate Zr(P0,)F(OSMe,),67 has the axial sites of the metal octahedra occupied by a fluoride ion and the oxygen of a solvent dimethyl sulfoxide molecule. Mg,[Be,(PO,) (OH)]-.6H,068 contains a new one-dimensional polymeric chiral beryllophosphate anion. Two other new non-centrosymmetric structures are the new titanyl phases Rb,Ti302(P0,),(HPO)2 and Rb3Ti,0(P,07)(P0,)3,69 however the short ‘titanyl’ Ti=O bond characteristic of the non-linear optical KTP (KTiOPO,) materials is barely apparent in these compounds and they show poor non-linear response.Other phosphorus-containing oxides i.e. phosphites and organophosphonates are beginning to be explored with reports of a new one-dimensional phosphite VO(H2P02),.2H2070 and two-dimensional phosphites CO(H,PO,),.~H,O~~ being studied. The latter series is capable of reversible topotactic water de-intercalation and also pyridine intercalation. Organophosphonates include the layered com-pounds (C2H 5NH3 )2 Cv303(H20)(PhP03)41 and c(c2 5 )4N1[(vo)3 (OH)(H20) (C,H5P03)3].H,0,73 and the 3-D framework ~?-CU(CH,PO,).~~ Other Oxyanion Derivatives.-Two reduced vanadium arsenates having 1-D chain structures have been reported,75 and two isostructural framework vanadium ar-senates A(VO),(AsO,) (A = Ba or Sr)76 have been described.A new berylloarsenate Be,(A~0,),.2H,0,~~ has been shown to contain bridged tetrahedral 3-rings. In the search for new non-linear optical materials two new early transition metal arsenates N~N~,AsO,~~ have been reported. A new mixed orthovana- and CS~T~,AS,O~,,~~ date-pyrovanadate series MBa2V301 or MBa,V,PO,, with M = Bi In or Ln has been discovered.” A model has been proposed for the structure of the new microporous titanosilicate ETS-10 using a combination of methods.81 The structure contains twelve-membered rings built from SiO tetrahedra and TiO octahedra and displays a considerable degree of disorder. A second porous titanosilicate is Na2Ti,03Si04.2H,0.82 With a view to understanding the mechanism of formation of the new mesoporous silicate materials (M41S) the structures of some heteronetwork clathrates of approximate compositions [NPhMe,],[Si,O (OH),] .38.7H20 and [NPhCH,Me3],02,].53.6H20 have been studied.83 The structure of a new mesopor- 66 S.S. Dhingra and R.C. Haushalter J. Solid State Chem. 1994 112 96. 67 D. M. Poojary B. Zhang and A. Clearfield J. Chem. SOC. Dalton Trans. 1994 2453. 6R C. Rob1 and V. Gobner 1.Chem. SOC.,Chem. Commun. 1994 2345. 69 W.T. A. Harrison T. E. Gier J.C. Calabrese and G. D. Stucky J. Solid State Chem. 1994 111 257. ’O A. Le Bail M.D. Marcos and P.Amoros Inorg. Chem. 1994 33 2607. M.D. Marcos P. Amoros D. Beltran and A. Beltran Inorg. Chem. 1994 33 1220. 72 M.I. Khan Y.-S. Lee C. J. O’Connor R.C. Haushalter and J.Zubieta Inorg. Chem. 1994 33 3855. 73 M.I. Khan Y.-S. Lee C.J. O’Connor R.C. Haushalter and J. Zubieta Chem. Mater. 1994 6 721. 74 J. Le Bideau C. Payen P. Palvadeau and B. Bujoli Inorg. Chem. 1994,33 4885. 75 R. C. Haushalter Z. Wang L. M. Meyer S. S. Dhingra M. E. Thompson and J. Zubieta Chem. Mater. 1994 6 1463. 7h S.-L. Wang and C.-Y. Cheng J. Solid State Chem. 1994 109 277. 77 W.T.A. Harrison T. M. Nenoff T. E. Gier and G.D. Stucky J. Solid State Chem. 1994 111 224. 78 W.T.A. Harrison C.S. Liang T. M. Nenoff and G. D. Stucky J. Solid State Chem. 1994 113 367. 79 K.-H. Lii J. Chem. Soc. Dalton Trans. 1994 2289. 8o J. Huang Q. Gu and A. W. Sleight J. Solid State Chem. 1994 110 226. M. W. Anderson 0.Terasaki T. Ohsuna A. Philippou S. P. MacKay A.Ferreira J. Rocha and S. Lidin Nature 1994 367 347. D. M. Poojary R.A. Cahill and A. Clearfield Chem. Mater. 1994 6 2364. ’’ J. Emmer and M. Wiehcke J. Chem. SOC.,Chem. Commun. 1994 2079. 430 P. Lightfoot ous aluminosilicate MCM-21 shows many unique and interesting features. This material has two independent pore systems both accessed by ten-ring openings one consisting of sinusoidal channels and the other large twelve-ring supercages of inner height 18.2 Three new condensed framework silicates BaVSi207,85 B~,SC,(S~O,),,~~ and Li,Ca,Si,O 3,87 have also been reported. A distorted phar- macosiderite analogue Na,H,(H,PO,),[(GeO)(GeO,),l .4H2Og8has been shown to contain both anions and cations as included species; both can be easily exchanged for a variety of other ions.Keszler et al. have prepared several new borate structure types the most notable being the huge 'STACK' family of stoichiometry A,M' M2(B0,),,89 of which over 150members are reported for large A cations and smaller +2 + 3 or +4 M M' cations. When M' = M2 are larger trivalent cations a new layered structure type is ob~erved.~' Powder diffraction data for the solid solution Ba,Y -xEu,(B03) has revealed the maximum size of M that the structure can tolerate. Three new beryllium borates and a zinc borate have been prepared and characterized for their interest as optical materials; Lil,Be5B(B03)g,91 BaBe,(B0,)292 and NaBe2B0,F,93 and Ba,Zn(B0,),.94 Several new selenites have been reported; Ga(HSeO,)(Se,O,).l .07H,0g5 is unusual in that it contains alternating anionic and cationic layers.Another layered phase is NH,(V02)3(Se0,)2,96 which has VO octahedra in a hexagonal tungsten bronze-like arrangement with the octahedra being 'capped' by SeOi-groups. A new mixed valent manganese selenite Mni1Mn~iO(Se0,),,97 has three crystallographicaily distinct MnO octahedra. Final- ly a new tellurate Na,Te,0g,98 has been reported. 5 Halides Chalcogenides etc. Oxyhalides Oxychalcogenides &.-Two new oxybromides M,Cu,O,Br (M = Sr Ba) have been reported." They are composed of planar cU30 sheets related to the CuO sheets in superconductors by the 'filling-in' of every alternate vacant square site with Cu intergrown with fluorite-type M,Br layers. A new tin oxyfluoride Sn,OF,,lOO has been prepared by hydrolysis of SnF,.The structure includes Sn" in four discrete crystallographic sites. The compound Sm,Ta,Cl,O lo' has been shown to consist of layers of Ta octahedral dimers alternating with layers of Sm face-capped trigonal prismatic dimers. BiCuOS and the isostructural selenides (MO)(CuSe) 84 M. E. Leonowicz J.A. Lawton S.L. Lawton and M. K. Rubin Science 1994 264 1910. 85 G. Liu and J. E. Greedan J. Solid State Chem. 1994 108 267. 86 L.-H. Wang L. F. Schneemeyer R. J. Cava and T. Siegrist J. Solid State Chem. 1994 113 211. '' M. E. Villafuerte-Castrejon A. Dago and R. Pomes J. Solid State Chem. 1994 112 438. " T. M. Nenoff W.T.A. Harrison and G.D. Stucky Chem. Muter. 1994,6 525. 89 K. I. Schaffers,P. D. Thompson T. A. Alekel 111 J.R. Cox and D.A. Keszler Chem. Muter. 1994,6,2014. 90 J. R. Cox D.A. Keszler and J. Huang Chem. Muter. 1994 6 2008. 91 J.L. Luce K. 1. Schaffers and D.A. Keszler Inorg. Chem. 1994 33 2453. 92 K.I. Schaffers and D.A. Keszler Inorg. Chem. 1994 33 1201. 93 L. Mei Y. Wang and C. Chen Muter. Res. Bull. 1994 29 81. 94 R. W. Smith and L. J. Koliha Muter. Res. Bull. 1994 29 1203. 95 R. E. Morris and A. K. Cheetham Chem. Muter. 1994 6 67. 96 J. T. Vaughey W. T. A. Harrison L. L. Dussack and A. J. Jacobson Inorg. Chem. 1994 33 4370. 97 M. Wildner J. Solid State Chem. 1994 113 252. 98 S. L. Tagg J.C. Huffman and J. W. Zwanziger Chem. Muter. 1994 6 1884. 99 W.J. Zhu F. Wu Y.Z. Huang C. Dong H. Chen and Z.X. Zhao Muter. Res. Bull. 1994 29 219. loo I. Abrahams S.J. Clark J. D. Donaldson Z.I. Khan and J.T. Southern J. Chem. Soo. Dalton Truns. 1994 2581. lo' G. Guo M. Wang J. Chen J. Huang and Q. Zhang J. Solid State Chem. 1994 113 434. New Compounds and Structures 431 (M = Bi Nd Gd Dy)lo2 have layered structures composed of alternating fluorite (BiO) units and tetrahedral (CuX) units. The MCuOSe (M = La Sm Y) analogues have also been reported.'03 An interesting new oxysulfide Ba,Ti,Sl,0,'04 may be considered as the first member of the family (BaO),(BaTiS,) formed by rearrange- ment of the infinite-chain BaTiS structure into a layered structure by inclusion of BaO. The oxynitride Na,W0,N'05 has been shown to adopt a wurtzite-like structure related to the low-temperature polymorph of Li,PO,. Three new oxyarsenide U,CU,ASO,'~~ structure types B~,M~,AS,O,'~~ and A,Zn,As,O (A = Ba Srj,lo8 have been reported.The latter is unusual in containing zinc in square planar coordination to oxygen. Sulfides.-Many new sulfide structures have been reported. An interesting new synthetic approach has been the use of supercritical amine solvents in the preparation of new phases in single crystal form. Kolis and co-workers have prepared several new frameworklog and low-dimensional' lo structures by this method. More 'traditional' soft-chemical routes have also been used. Thus hydrothermal techniques have been used to prepare post-transition metal sulfides such as Sn,S,.(NMe,),.H,O (Figure 12),," Cs,Sn5S,,.2H,0,112 Sn5S,0,[HNMe,],,"3 [MeNH,],Sb,S, (Figure 13),ll4 and [Me,N],Ge,S,,.' l5 Many new framework and layered topologies have been discovered and it is clear that this is a rich source of new materials for future work.Soft chemical methods have been used to prepare the new binary sulfide Re$ ,' by topotactic oxidative deintercalation of Na,Re,S ,. The structure consists of Re$ octahedral clusters linked into chains via S-S bridges. The first 'self-misfit' layer compound (Nb -,La,S)NbS, has been prepared and characterized.' l7 The com- pound differs from the normal misfit-layer type 'LaNbS,' by a 45" rotation of the 'NbS' subsystem. Other mixed metal sulfides reported include the AMTeS series"8 (A = K Rb Cs; M = Cu Ag) containing the new trigonal pyramidal polychalcogenide anion TeSi -and two antimony sulfides containing polysulfide anions Cs,Sb,S and CsSbS,.' Selenides and Tellurides.-Cs,M,(P,Se j5 (M = Sb Bi) contain P,Se:- anions in three unique bonding modes leading to a staircase layered framework featuring weak 102 A.M.Kusainova P.S. Berdonosov L.G. Akselrud L.N. Kholodkovskaya V. A. Dolgikh and B. A. Popovkin J. Solid State Chem. 1994 112 189. 103 W.J. Zhu Y.Z. Huang C. Dong and Z.X. Zhao Mater. Res. Bull. 1994 29 143. in4 A.C. Sutorik and M.G. Kanatzidis Chem. Mater. 1994 6 1700. 105 S. H. Elder F. J. DiSalvo J. B. Parise J. A. Hriljac and J. W. Richardson J.Solid Stute Chem. 1994,108 73. 106 S.L. Brock H. Hope and S. M. Kauzlarich Inorg. Chem. 1994 33 405. 107 D. Kaczorowski M. Potel and H. Noel J. Solid State Chem. 1994 112 228. 108 S. L. Brock and S.M. Kauzlarich Inorg. Chem. 1994 33 2491. 109 P.T. Wood W.T. Pennington and J.W. Kolis Inorg. Chem. 1994 33 1556. 110 J. E. Jerome P. T. Wood W. T. Pennington and J. W. Kolis Inorg. Chem. 1994 33 1733. 111 J. B. Parise Y. KO J. Rijssenbeek D. M. Nellis K. Tan and S. Koch J.Chem.SOC.,Chem. Commun. 1994 527. 112 Y. KO C.L. Cahill and J.B. Parise J. Chem. SOC.,Chem. Commun. 1994 527. 113 J. B. Parise and Y. KO Chem. Muter. 1994 6 718. 114 X. Wang and F. Liebau J. Solid State Chem. 1994 111 385. 115 J.Y. Pivan 0. Achak M. Louer and D. Louer Chem. Mater. 1994 6 827. 116 A. Nemudry and R. Schollhorn J. Chem. Soc. Chem. Commun. 1994 2617. 1 I7 R. Roesky A. Meerschaut A. van der Lee and J. Rouxel Muter. Res. Bull. 1994 29 1149. 118 X. Zhang and M.G.Kanatzidis J. Am. Chem. Soc. 1994 116 1890. 119 T.J. McCarthy and M.G. Kanatzidis Inorg. Chem. 1994 33 1205. 432 P. Lightfoot Figure 12 Crystal structure of Sn,S,.(NMe,),.H,O (Reproduced from J. Chem. Soc. Chem. Commun. 1994 527) Figure 13 The structure of [Me,NH,],Sb,S, (Reproduced by permission from J. Solid State Chem. 1994 111 385) M-M interactions.12' Two unusual fluorochalcogenides BaCuFQ (Q = S Se) have been reported. They have tetragonal layered structures and may be viewed as intergrowths of fluorite-type [Ba,F,] and anti-fluorite-type [CU,Q,].'~' Exploratory lZo T.J. McCarthy T. Hogan C. R. Kannewurf and M.G. Kanatzidis Chern. Muter. 1994 6,1072. lZ1 W.J. Zhu Y.Z. Huang F. Wu C. Dong H.Chen and Z.X. Zhao Muter. Res. Bull. 1994 29 505.New Compounds and Structures 433 telluride chemistry has been very productive. Electrochemical methods have been used to synthesize several new one-dimensional materials containing tetraalkyl ammonium cations.' 22-1 24. Solid-state methods have also produced interesting new chain corn pound^.'^^^'^^ Two modulated structures in the series MA,Te (M = Nb Ta;A = Si Ge) have been st~died;'~~,'~~ TaSi,,,,,Te has an incommensurate superstructure which can be considered as a succession of commensurate domains of TaSi,,,Te and TaSi,,,Te structures. N~,F~CU,~,,T~,~~~ contains Nb,Fe,Cu,Te units stacked together to produce chains with one-dimensional extended metal-metal bonds. Halides.-The major effort has been in metal halide cluster chemistry by Corbett and co-~orkers.'~~ Extended lattice compounds have also been studied.An interesting new series of metallic tin halides has been re~0rted.I~' These materials have layered structures related to the Ruddlesden-Popper phases but differ in having quaternary ammonium cations between perovskite-like tin halide sheets (see for example Figure 14). Variable chain length alkyl groups in the cation allow a great deal of tunability of the conducting properties. another example of combined 'molecular' and 'extended lattice' solid state chemistry is in the stabilization of NbI monomers in the layered structure of Nb,S,I, (Figure 15).13' Gd,I,Mn13 contains distorted double chains of Gd,Mn edge-sharing octahedra. The isostructural series MMnZrF (M = T1 Rb NH, K) is unusual in containing seven-coordinated Mn2 in alternating edge-shared + pentagonal bipyramids with Zr4 + linked together to form a three-dimensional framework.Nitrides &..-New synthetic routes to nitrides are receiving increasing attention due to their potentially interesting structure and properties. LiWN,', has been prepared by the reaction of Li2W0 and NH at elevated temperature. The compound is metallic and is isostructural with LiMoN, having a layered structure with trigonal prismatic W5+. The identification of the subnitrides Na,,Ba,N and Ag,,Ca,N previously reported as Ag,Ca, containing discrete Ba,N octahedra suggest that subnitride chemistry may be more common than expected.', A new quaternary nitride Li3Ba2NbN,,l3 has also been reported; Nb is tetrahedrally coordinated by N.An exciting development has been the discovery of superconductivity above 20 K in the borocarbides LnNi,B,C. The compound LuNi2B2C has been shown to adopt a 122 C. J. Warren S.S. Dhingra R.C. Haushalter and A. B. Bocarsly J. Solid State Chem. 1994 112 340. 123 C. J. Warren R.C. Haushalter and A.B. Bocarsly Chem. Mater. 1994 6 780. 124 S.S. Dhingra C. J. Warren R.C. Haushalter and A. B. Bocarsly Chem. Muter. 1994 6 2382. J. A. Cody and J.A. Iberts Inorg. Chem. 1994 33 2713. 126 S.S. Dhingra and R.C. Haushalter Chem. Mater. 1994 6 2376. 12' A. van der Lee M. Evain L. Monconduit R. Brec and V. Petricek Inorg. Chem. 1994 33 3032. 12' M. Evain A. van der Lee L. Monconduit and V. Petricek Chem.Mater. 1994 6 1776. 129 J. Li F. McCulley M. J. Dioszeghy S. C. Chen K.V. Ramanujachary and M. Greenblatt Inorg. Chem. 1994 33 2109. 130 D. B. Mitzi C. A. Feild W.T.A. Harrison and A.M. Guloy Nature 1994 369 467. 13' G.J. Miller and J. Lin Angew. Chem. Int. Ed. Engl. 1994 33 334. 132 M. Ebihara J. D. Martin and J. D. Corbett Inorg. Chem. 1994 33 2079. 133 M. El-Ghozzi D. Avignant and M. Guillot J. Solid State Chem. 1994 108 51. 134 P. Subramanya Herle M. S. Hegde N.Y. Vasanthacharya J. Gopalakrishnan and G.N. Subanna J. Solid State Chem. 1994 112 208. 13' G.F. Snyder and A. Simon Angew. Chem. Int. Ed. Engl. 1994,33 689. X. Z. Chen and H. A. Eick J. Solid State Chem. 1994 113 362. 434 P . Lighgoot Figure 14 Schematic crystal structure of (C,H,NH3)2(CH3NH3),Sn3110 (Reproduced by permission from Nature 1994 369 467) variant of the ThCr,Si structure-type with additional carbon in the Lu plane.13' LuNiBC is derived from LuNi,B,C by adding another Lu-C layer (Figure 16).Gd,B3C2 adopts another new structure type related to that of YBC by incorporation of extra non-metal linking zigzag carbon-branched boron chains.' 38 Finally U,RuSi3 has been prepared and found to have an ordered AlB structure with Ru and Si ordered over a two-dimensional s~b-lattice.'~~ 13' T. Siegrist H. W. Zandbergen R. J. Cava J. J. Krajewski and W. F. Peck Jr. Nature 1994 367 254. lJs F. Wiitkar J.-F. Halet J.-Y. Saillard P. Rogl and J. Bauer Znorg. Chem. 1994 33 1297. lJ9 R. Pottgen P. Gravereau B. Darriet B. Chevalier E.Hickey and J. Etourneau J. Muter. Chem. 1994,4 463. New Compounds and Structures Figure 15 Structure of Nb,S21, (Reproduced by permission from Angew. Chem. Znt. Ed. Engl. 1994 33 334) Figure 16 Crystal structures of LuNi,B,C and LuNiBC (Reproduced by permission from Nature 1994 367 254)