摘要:
1976 1943Nitrosyl Complexes of Rhenium. Part 2.l Crystal and Molecular Structureof Di hydridonitrosyltris(triphenylphosphine)rhenium( i)-Benzene(2/1)By Gianfranco Ciani,' Domenico Giusto, and Mario Manassero, Centro di sintesi e struttura dei composti dicoordinazione nei bassi stati di ossidazione del C.N.R., lstituto di Chimica Generale ed Inorganica, ViaVenezian 21, 20133 Milano, ItalyAlberto Albinati, lstituto di Chimica delle Macromolecole del C.N.R., Via Corti 12, Milano 201 33, ItalyThe crystal and molecular structure of the title compound has been determined by Patterson and Fourier methodsfrom three-dimensional X-ray data collected by diffractometer. Crystals are orthorhombic, space group Pca2,. withcell constants a = 25.069(6), b = 18.737(4), and c = 20.644(5) 8.The structure has been refined by least-squares methods to R 0.048 for 2 938 independent reflections. The two crystallographically independent moleculesin the asymmetric unit are very similar and exhibit markedly distorted octahedral geometry, with one phosphineligand, the NO group, and the two hydrido-ligands (mutually cis) in equatorial positions, with the other twophosphine ligands axial, largely bent toward the hydrido H atoms. The three Re-P distances are 2.370(7),2.439(7), and 2.403(8) a in the first molecule and 2.401(6), 2.498(8), and 2.386(8) 8 in the second. Thenitrosyl groups are linked linearly to the metal atoms, as NO+ linands, with Re-N 1.77(2) and 1.73(2) and N-01.25(3) and 1.24(3) 8 in the two molecules.P-Re-P angles [143.4(3) and 143.0(3)"].WE are currently studying the stereochemistry of somemononitrosyl complexes of rhenium obtained from thepentahalogenonitrosyl species [ReX,(NO)l2-.Thestructures of the anions [ReBr,(NCMe) (NO)]- and[ReBr,(NO) (HOEt)]- have already been rep0rted.l Aderivative recently obtained is the diamagnetic complex[ReH2(NO)2(PPh3)3],3 the second example of a hydrido-nitrosyl complex of rhenium to be reported, the firstbeing [ReH(NO),(PPh3),].3 The i.r. spectrum of thecomplex exhibits two bands (1 950 and 1 800 cm-l) as-signed to the Re-H stretching modes, indicating a cisconfiguration for the two hydrido-ligands; it also shows arather low v(N0) frequency at 1640 cm-1.2 Since theligand arrangement in this type of complex is very oftenhighly distorted from ideal geometry, owing to the lowsteric hindrance of the hydrogen ligands, and since thissteric factor could have some effect on metal-nitrosyl in-teraction, we have undertaken an X-ray single-crystalanalysis in order to ascertain its stereochemistry and toestablish the nature of the Re-NO bond.EXPERIMENTALCrystal Data.-C,,H,,NOP,Re, M = 1 044.2, Orthorhom-bic, a = 25.069(6), b = 18.737(4), c = 20.644(5) A, U =9 696.9 A3, D, = 1.41(2) (by flotation), 2 = 8, D, = 1.431,F(000) = 4 216.Space group Pca2, (no. 29) or Pcam (non-standard setting of Pbmz, no. 57), from systematic absences.Mo-K, radiation, A = 0.7107 A; p(Mo-K,) = 27.9 cm-l.Intensity Measurements.-The crystal used for data collec-tion was an elongated prism 0.06 x 0.07 x 0.27 mm.Intensity measurements were made on a Philips PW 1100automatic diffractometer, by the 8-26 scan method, and withgraphite-monochromatized radiation, scan range 1.2", scanspeed 0.04" s-l, with background counts of 15 s taken oneach side of the scan.The total number of reflections,collected within 28 < 46", was 6 977. Three standard re-flections, measured at regular intervals, showed no evidenceof crystal decay. Integrated intensities were corrected for1 Part 1, G. Ciani, D. Giusto, M. Manassero, and M. Sansoni,D. Giusto, G. Ciani, and M. Manassero, J . OrganonzetallicJ.C.S. Dnltow, 1975, 2156.Chem., 1976, 105, 91.The largest deviation from ideal geometry is shown' by the axialLorentz and polarization factors.Transmission factors,calculated by the Busing and Levy method * for a sample ofreflections, were in the range 0.70-0.74, so no absorptioncorrection was applied. A final set of 2 938 independentnon-zero reflections, having o(I)/I < 0.26, were used in thesolution and refinement of the structure.Determination and Refinement of the Structure.-Thestructure solution was based on a three-dimensional Patter-son map, which showed the positions of the rhenium atoms.We first assumed the centrosymmetric space group Pcam,which would require the presence of one molecule in theasymmetric unit. After a preliminary refinement of therhenium atom a successive difference-Fourier map showedmost of the remaining non-hydrogen atoms. While ratherbroad peaks were observed for one phosphorus atom and theNO group atoms, all the other atoms clearly showed doubleimages.We therefore then undertook refinement in thenon-centrosymmetric space group Pca2,, with two crystallo-graphically independent [ReH,(NO) (PPh,),] molecules. Re-finements were carried out by block-matrix least squares,with the phenyl rings constrained to rigid-body motion(D6?& symmetry, assuming C-C 1.392 A). Anisotropic tem-perature factors were used for the Re and P atoms; anaverage isotropic thermal factor was assigned to each phenylring. During these refinements small oscillations were ob-served for some positional parameters of P(2), N(l), and0 ( 1 ) atoms in the first molecule and, correspondingly, ofP(5), N(2), and O(2) atoms in the second one, indicatingsome correlation between the parameters of these pairs ofatoms. After several cycles of refinement a difference-Fourier synthesis revealed the presence of a solvent benzenemolecule, which was refined rigidly with DSh symmetry.Allthe non-hydrido-hydrogen atoms were located in fixed idealpositions (C-H 1.08 fi) and their contributions introducedinto the structure-factor calculations. At this stage ano-malous scattering was also taken into account (for rheniumand phosphorus) and refinements were made in order toestablish the correct structure enantiomorph. The finalvalues of the agreement indices R and R' were 0.048 and0.059 {R' = [Cw(lFol - KIFcl)2/Zw~FoIz]*}. Weights wereassigned according to the formula w = 1/(A + BIFo\ +CIFo\z) where, in the final stages of refinements, A wasG.La Monica, M. Freni, and S. Cenini, J . OrganometallicChem., 1974, 71, 57.W. R. Busing and H. A. Levy, A d a Cryst., 1957, 10, 180J.C.S. Dalton215.4, B - 1.83, and C 6 x in order to obtain a con- Re-H 1.44 A, and H-Re-H 89". These results are rather un-stant distribution of the weighted mean quadratic errors as satisfactory because of the too short Re-H distances, anda function of sinell and F,. Atomic scattering factors give only a rough indication of the hydride atom positions.were taken from ref. 5 for non-hydrogen atoms, and from We also made an indirect determination through poten-ref. 6 for hydrogen. Corrections for both the real and im- tial-energy calculations.Energy maps were computedaginary parts of the anomalous scattering were taken from taking into account all the non-bonding intramolecularX- 10 819(4)-238(2)-1 656(2)-1 645(3)38 312(4)4 769(2)3 542(2)3 043(3)-1 132(9)- 1 196(7)3 779(8)3 713(7)interactions of a hydrido-ligand by scanning a spherical sur-TABLE 1Positional and thermal parameters of non-group atoms *Y-4 094(6)-45 362(6)- 227 (4)-22(4)- 4 350(3)-5 026(4)-433(4)- 4 739(3)- 1 346(12)- 2 006( 11)- 3 619(11)- 2 966(11)z0- 16 696(6)- 490( 3)- 953(3)873(3)- 1 531(3)- 524(4)-2 141(3)77(12)90( 11)- 1 754(11)- 1 825(10)* Estimated standard deviation in the last significant figure is given in parentheses here and in succeeding Tables.The ReAnisotropic temperature factors are given by exp - (h2bll parameters x lo5; others except for the isotropic B factors (A2), x lo4. + k2bz2 + l2b33 + hkb,, + hlbl, + kZbZ3).The final difference-Fourier synthesis, apart from theregions surrounding the two rhenium atoms, which will beexamined later, showed some residual peaks, not > 0.6eA-3, close to phenyl carbon atoms, and deriving veryprobably from the assumption of an average thermal factorfor all the atoms of a ring.The Hydrido-hydrogen A toms.-In the final part of thestructural determination we attempted to locate the hydrido-hydrogen atoms by the method of La Placa and Ibers.* Wecompared four difference syntheses, computed at decreasingsinO/A, namely at 0.55, 0.45, 0.35, and 0.25, correspondingto 2 938 (all data), 2 230, 1276, and 519 independent re-flections.In the first map two peaks (0.66 and 0.71 eA-,)were found around Re( 1) near to the expected positions forthe hydrido-ligands, with Re-H 1.57 A in both cases andH-Re-H 100". Around Re(2) a suitable peak (0.80 eA-3)was observed, with Re-H 1.75 A, but in the position ex-pected for the other one only a very broad peak was found,probably deriving from the overlap with other residualpeaks due to the heavy atom. In the second map also thefourth hydride peak became apparent. However, thepresence of residual heavy-atom peaks, in different positionsfrom map to map and overlapping with the hydride peaks,seemed to lower significantly the reliability of the analysis.In fact, the hydride atom positions seemed to change in thevarious maps, with variations in Re-H up to ca.0.30 A.Using the criterion of the maximum p : o(p) ratio, the bestsituation was the following: (i) the two peaks around Re( 1)were found to lie in the Re(l),P(2),N(l) plane, with Re-H1.57 and 1.41 A, and a H-Re-H 91"; (ii) the two peaksaround Re(2), lying in the Re(2),P(5),N(2) plane, both had* See Notice to Authors No. 7 in J.C.S. Dalton, 1975, Indexi5sue (items less than 10 pp. are supplied as full size copies).D. T. Cromer and J. B. Mann, Acta Cryst.. 1968, A24, 321. ;T. B. Forsyth and M. Wells, Acta Cryst., 1959, 12, 412. '* S. J. La Placa and J. A. Ibers, Acta Cryst., 1965, 18, 511.International Tables for X-Ray Crystallography,' vol.3,Kynoch Press, Birmingham, 1962.face centred at the rhenium atom, a procedure already adop-ted for [ReH,(Ph,PC,H,PPh,),] (ref. 9) and [ReH,(PPh,),-(Ph,PC,H,PPh,) J .lo Each interaction was computed as Vi= aiexp( -birz) - C ~ Y ; ~ , with a, b, and c taken from ref. 11for H-P, and from ref. 12 for H-0, H-N, H-C, and H-H in-teractions. The Re-H distance was assigned values 1.70and 1.60 A, typical for this type of interaction. In bothcases two very clear minima were found around each rheniumatom. These minima lay fairly well in the equatorial mo-lecular planes Re(l),P(2),N(I) and Re(2),P(5),N(2) andformed H-Re(1)-H and H-Re(2)-H of 100 and 101" (Re-H1.70 A) and of 99 and 102" (Re-H 1.60 A).Conzputations.-All computations were made on aUNIVAC 1106 computer.Local programs were used fordata reduction, statistical analysis of weighting schemes, andnon-bonding energy calculations. In addition, local ver-sionsof entries nos. 7528, 7531, 7532, and 7535 in the 1966' International World List of Crystallographic Programs 'were used for Fourier analysis, and structure-factor and least-squares calculations; Johnson's ORTEP was used forthermal ellipsoid plotting and a program by Donienicanoand Vaciago for computation of molecular parameters.The results of the refinements are reported in Tables 1and 2. Final observed and calculated structure factors arelisted in Supplementary Publication hTo. SUP 21786 (4 pp.,1 microfiche). *DISCUSSIONThe crystal structure of the complex consists of thepacking of discrete [ReH,(NO) (PPh,),] and benzeneS V.G. Albano and P. L. Bellon, J . Organometallic Chem.,l o V. G. Albano, P. L. Bellon, and V. Scatturin, Rend. 1st.11 F . G. Calascibetta, M. Dentini, P. De Santis, and S. Moro-l2 P. De Santis and A. M. Liquori, Biopolymers, 1971, 10, 699.1972, 37, 151.Lomb. Sci. Lett., 1966, A100, 989.setti, Biopolymers, 1975, 14, 16671976 1945TABLE 2 (Continued)AtomC(111)C(112)C(113)C( 114)C(115)C(116)C(121)C(122)C(123)C( 124)C(125)C(126)C(131)C(132)C(133)C(134)C(135)C( 136)C(211)C(212)C(213)C(214)C(215)C(216)C(221)C(222)C(223)C(224)C(225)C(226)C(231)C(232)C(233)C(234)C(235)C(236)C(311)C(313)C(314)C(315)C(316)C(321)C(322)C(324)C(325)C(326)C(331)C(332)C(312)C(333)C(333)C(334)C(335)C(336)C(411)C(412)C(413)C(414)C(415)C(416)C(421)C(422)C(423)C(424)C(425)C(426)C(431)C(432)C(433)C(434)C(435)C(436)C(511)C(512)C(513)TABLE 2Parameters of the group atoms a s bx152(7)115(7)670(7)966(5)706(7)170(9)181(8)- 143(5)- 178(11)- 156(11)- 506(9)-516(8)232( 10)418(9)760(11)9 17( 10)731(9)388( 11)- 2 338(9)- 2 444(8)- 2 934(10)- 3 318(9)- - 3 212(8)- 2 722(10)- 1 360(11)-985(11)- 719(8)- 829(11)- 1 205(11)-1 470(8)-1 835(13)- 1894(10)- 2 042(7)- 3 130(13)- 2 071(10)- 1924(7)- 1948(12)- 2 476(11)- 2 675(8)- 2 347( 12)-1 819(11)-- 1619(8)-2 205(9)- 2 696(10)-- 3 082(8)-- 2 486(10)-1 306(11)- 852(10)- 620(9)- 843( 11)- 1 297(10)-1 528(9)-- 2 977(9)--2 iOO(8)5 222(8)5 065( 7)5 411(9)5 915(8)6 072(7)5 726(9)5 050(10)4 781(8)4 970(9)5 429(10)5 698(8)5 508(9)5 014(11)4 979(10)5 118(7)5 290(11)5 324(10)5 186(7)2 857(7)2 574(8)2 052(6)Y-1 O l O ( 8 )- 1 625(11)-2 267(8)-2 295(8)-1 681(11)-1 038(8)334(12)151(12)552( 13)1 136(12)1319(12)91 8( 13)2 35 (1 5)928( 14)1231(11)840(15)146 ( 14)-155(11)- 783( 18)-1 232(16)-1 577(14)-1 475(18)-1 027(16)- 681(14)-1 035(13)- 788( 10)-1 268(14)-1 994(13)-2 241(10)-1 762(14)359 (12)401 (1 3)1044(17)1 644(12)1603(13)960 ( 1 7)- 744( 13)- 750(13)-1 338(17)-1 921(13)-1 915(13)-1 327(17)564( 12)346( 10)85 1 ( 14)1 574(12)1 792(10)1287(14)431(15)817(12)1278(15)1353(15)966(12)505( 15)- 3 982(10)-3 310(12)- 2 827( 10)-3 498(12)-4 076(9)-5 121(13)-5 681(13)-5 960(ll)-5 678(13)-5 119(13)-4 840(11)-5 375(11)-5 188(9)-5 681(12)-6 361(11)-6 547(9)-6 054(12)- 3 984( 17)-4 161(14)-3 923(15)-2 733(9)- 716(11)- 837(11)-963(11)- 968( 11)- 847( 11)-721(11)-1 217(9)-1 714(12)-2 281(10)-2 351(9)- 1 854(12)-1 287(10)66(11)434( 13)974(11)1061(10)607 ( 1 3)-20(10)- 870(11)- 348( 11)- 303( 10)-781(11)- 1 303(11)- 1 347(10)- 1 563(12)-2 006(14)-2 408( 12)- 2 366( 12)- 1 922( 14)- 1 521(12)-1 382(15)-2 051(15)-2 339(11)-1 957(15)-1 287(15)-1 OOO(11)1388(14)1597(15)1930(15)2 054(14)1 846(15)1513(15)672( 13)427 (1 3)269( 13)356(13)601 (1 3)759( 13)1522(11)1356(9)1 804(13)2 418(11)2 584(9)2 136(13)- 1 681(12)-1 464(11)-1 518(12)- 1 789(12)-2 005(11)-1 951(12)- 782(10)-482(12)98(12)379( 10)80(12)-500(12)-2 133(10)-2 785(11)-3 261(8)-3 085(10)-2 434(11)-1 958(8)-403(9)153(9)232(8)AtomC(514)C(515)C(516)C(521)C(522)C(523)C(524)C(525)C(526)C(531)C(532)C(533)C(534)C(535)C(536)C(611)C(612)C(613)C(614)C(615)C(616)C(621)C(622)C(623)C(624)C(625)C(626)C(631)C(632)C(633)C(634)C(635)C(636)C(1)C(2)C(3)C(4)C(5)3?12)H(113)H(114)H(115)H(116)H(122)H(123)H(124)H( 125)H(126)H(132)H(133)H(134)H(135)H(136)H(212)H(213)H(214)H(215)H(216)H(222)H(223)H(224)H(225)H(226)H(232)H(233)H(234)H(235)H(236)H(312)H(313)H(314)H(315)H(316)H(322)H(323)H(324)X1813(7)2 097(8)2 619(6)3 945(8)3 739(6)4 059(9)4 583(8)4 789(6)4 470(9)3 577(11)3 448( 10)3 578(11)3 708(7)3 707(10)2 581(11)2 812(8)2 490(12)1 938(11)1707(8)2 029(12)2 617(10)2 681(8)2 408(10)2 070(10)2 006(8)2 279(10)3 181(11)2 789(8)2 885(9)3 373(11)3 767(8)3 671(9)4 339(12)4 131(8)4 468( 12)5 014(12)5 222(8)4 884(12)- 575-1148721398937435454- 147- 769- 7883 447(7)2969051184853244-2 145-3 016-3 700-3 511-2 640- 899- 426- 622-1 290-1 762-1 825-2 087-2 244-2 140-1 877-2 731-3 086-2 502-1 562-1 208-2 778-3 464-3 277Y-3 508(17)-3 331(14)-3 569(15)-3 639(10)-2 949(12)-2 384(9)-2 509(10)-3 199(12)-3 761(9)-5 092(11)-5 773(13)- 6 346( 10)- 6 239( 11)-5 558(13)-4 985(10)-4 380(16)-3 777(17)-3 253(13)-3 332(15)- 3 934( 17)-4 458(13)-5 624(12)-6 357(13)-6 827(9)- 6 564( 12)-5 831(13)- 5 361(9)-5 608(13)-5 699(14)-6 134(13)-6 479(13)-6 388(14)- 5 953( 13)-2 125(17)-2 561(18)-2 998(13)-3 OOO(17)-2 564(18)-2 127(13)-1 603-2 746-2 795-1 702- 559- 3024101 44917741060123317711075- 157- 695-1 311-1 926-1 744- 946- 332- 222-1 075-2 368-2 807-1 953- 6510772 1452 071928- 395-1 341-2 379-2 369-1 322-2166811968d-246(9)- 803(9)- 882(8)- 156(12)-141(12)62(13)251(12)235( 12)31(13)79( 10)288( 12)936( 10)727(12)- 140(8)1 156(8)- 2 480( 15)-2 757(16)-3 032(15)- 3 029( 15)-2 752(16)- 2 477( 15)-1 625(11)- 1 701(10)- 1 299( 12)- 743 (10)- 1 146( 12)-2 870(10)-3 339(13)- 3 873( 11)-3 937(10) - 3 469( 13)-2 935(11)-3 989(13)-3 505(15)-3 146(13)- 3 271(13)- 3 755(15)- 4114(13)- 832-1 056-1 065- 850- 627-1 668-2 668-2 793-1 909- 899- 440- 819(11)3671329148367424103- 746-1 675-1 754-2 038-2 752-2 678-1 890-1 175-2 348-2 859-2 180- 990- 4781 5002 0922 3141943135136079231946AtomH(325)H(326)H(332)H(333)H(334)H(335)H(336)H(412)H(413)H(414)H(415)H(416)H(422)H(423)H(424)H(425)H(426)H(432)H(433)H(434)H(435)H(436)H(512)H(513)H(514)H(515)H(516)H(522)H(523)H(524)H (525)H(526)H(532)H(533)H(534)H(535)H(536)H(612)H(613)H(614)H(616)H(616)H(622)H(623)H(624)H(625)H(626)H (632)H(633)H(634)H(635)H(636)H(1)H (2)H(3)H (4)H(5)H(6)XTABLE-2 403-1 717- 678-266- 662-1 470-1 8814 6735 2906 1866 4655 8494 4244 7615 5776 0565 7184 8465 0915 3985 4595 2132 7601 8321 40719112 8403 3313 8994 8325 1984 6313 3473 3483 5793 8093 8083 2422 6691688127818502 9452 4591 8581 7442 2302 4082 5793 4484 1483 9774 0773 7064 3075 2785 6485 0472 (Continued)Y2 3551 457759158017121025205-3 236-2 209-2 377-3 572- 4 598-5 900-6 395-5 895-4 900-4 404-4 659-5 536-6 744-7 075-6 199-4 433-4 060-3 322-3 008-3 431-2 851-1 847-2 069-3 296-4 301-5 856-6 876-6 685-5 474-4 454-3 716-2 783-2 923-3 994-4 927-6 561-7 398-6 930-5 626- 4 789-5 430-6 205-6 817-6 656-5 882-1 784-2 559-3 337-3 340-2 565-1 787z6699508791 6752 7673 0632 266-1 253-1 350-1 830-2 215-2 120- 701332832299- 733-2 921-3 767-3 455-2 297-1 450527666- 184-1 175- 1 315- 2877541038219- 64411812711661899-2 759-3 248-3 243-2 749-2 260-2 074-1 358- 505- 369- 1 086-3 288-4 238-4 353-3 519-2 569-4 269-3 407-2 768-2 990-3 851-4 4910 x , y , z x lo4.b Isotropic mean thermal parameters of the19 groups are 3.2(2), 4.8(3), 5.4(3), 4.9(4), 4.9(3), 5.6(3), 5.8(4).4.8(3), 4.6(3), 4.1(3), 4.3(3), 4.0(3), 4.3(3), 4.4(3), 4.4(3), 6.7(4),4.5(3), 5.0(3), and 8.1(5) Hiz. c Carbon atoms of the benzenemolecule. Hydrogen atoms have the same labels and thermalfactors as the carbon atoms to which they are linked.solvent molecules in the ratio 2 : 1.All the intermolecu-lar contacts are normal, except for some involving phenylhydrogen atoms, which were somewhat shorter than thesum of the van der Waals radii, probably owing to therigid-body refinement of the phenyl groups and to thelocation of the hydrogen atoms in idealized positions.Figwe 1 shows a projection of the structure down the caxis.J.C.S. DaltonThe two crystallographically independent [ReH,(NO)-(PPh,)J molecules exhibit similar geometries, especiallyin their inner co-ordination spheres (Figure 2). We shallrefer to the molecule containing Re(1) as molecule (I) andto the other as molecule (11). All the important inter-FIGURE 1 Projection of the structure down the G axisFIGURE 2 ORTEP drawing of the inner co-ordination spherein the two independent [ReH,(NO) (PPh,),] moleculesatomic distances and angles are reported in Table 3.Therhenium atoms show strongly distorted octahedral co-ordination, with one phosphine ligand, the nitrosyl group,and the two hydrido-ligands (themselves cis) lying inequatorial positions, the other two phosphine ligands beingaxial and markedly bent towards the hydrido-atoms.Howeverthey are of two types: axial, mean 2.39 A, and equatorial,both these being longer as a consequence of the structuraltrans influence of the hydrido-ligands. These distances[Re(l)-P(2) 2.439(7), and Re(2)-P(5) 2.498(8) A] exhibitthe largest difference between corresponding bond lengthsin the two molecules, probably to some extent due tol3 See, for example, V.G. Albano, P. L. Bellon, and G. Ciani,J. O~ganometallic Chetn., 1971, 31, 75 and refs. therein.All the Re-P distances are as expected.11976 P 947correlation in the refinement of the positional para-meters of P(2) and P(5), leading to not too accurateTABLE 3Selected interatomic distances and angles in the two[ReH,(NO) (PPh,)J molecules(a) Distances (A)Molecule (I)Re( 1)-P(l)Re(1)-P(2)Re(1)-P(3)Re( 1)-N( 1) :/;)T:;!l)P(l)--C(121)P(l)-c(131)P(2)-C(211)P( 2)-c (22 1)P(2)<(231)P(3)<(311)P( 3)-C (32 1)P( 3)-C (3 3 1)P(l) * P(2)P(2) * * * P(3)P(3) - - * N(l)P(l) * * * N(l)P(2) * - * N(l)(b) Angles (")Molecule (I)P(1)-Re( 1)-P(2)P( 1 )-Re ( 1 ) -P( 3)P (2)-Re (1 )-P (3)P ( 1 )-Re( 1) -N ( 1)P(2)-Re(l)-N( 1)P(3)--Re(l)-N(l)Re(l)-N(l)-O( 1)Re (1)-P( I)< (1 1Re ( 1 )-P( 1 )-C ( 1 2Re ( 1) -P( 1 ) -C ( 1 3Re(l)-P(2)-C(212.370 (7)2.439(7)2.403( 8)1.77 (2)1.25(3)1.83(2)1.84(2)1.86(3)1.84(3)1.85( 3)1.79(3)1.88 (3)1.83(3)1.80(3)3.70(1)3.85(1)3.29(2)3.03 (3)3.24(3))Re(l)-P(2j-C(221)Re( l)-P(2)-C(231)Re( 1 )-P( 3)-C (3 1 1)Re ( 1 )-P (3) -C (32 1 )Re( l)-P(3)-C(331)C(ll1)-P( l)-C( 131)c ( 1 1 1)-P( 1 )-c ( 12 1)C(l2l)-P(l)-C( 131)C(21 l)-P(2)-C(221)c (22 1)-P( 2)-C( 2 3 1)C( 32 1)-P( 3)-c (33 1)C(211)-P(2)-€(231)C( 31 l)-P(3)-C(321)C(31 l)-P(3)-C(331)100.6 (2)143.4( 3)105.3(2)104.2(8)90.7(8)1 0 1.0 (8)175(2)1 18.2( 7)120.3( 9)11 1.6( 8)1 1 8.7 (8)109.0( 9)122.2 ( 10)1 16.4( 9)1 17.5/9)115.0(10)102(1)l O l ( 1 )l O l ( 1 )96(1)96(1)103(1)106(1)105(l)104(1)Molecule (11)Re( 2)-P(4)Re (2)-P( 5)Re( 2)-P( 6)Re (2)-N (2)P(4)-C(421)P(4)--C(431)P(5)-C(511)P(5)-C(521)P(5)-C(531)P(6)-C(611)P(6)-C(621)P(6)-C(631)rfs;:;2((:!1)P(4) * * P(5)P(5) * * * P(6)P(4) * * * N(2)P(5) * * * N(2)P(6) + - - N(2)Molecule (IT)P( 4)-Re( 2)-P (5)P(4)-Re(2)-P( 6)P( 5)-Re (2)-P( 6)P(4)-Re(2)-N(2)P( 5)-Re (2)-N (2)P ( 6)-Re( 2)-N (2)Re(2)-N(2)-0(2)Re(2)-P(4)-C(411)Re (2)-P( 4)-C (42 1)Re (2)-P(4)-C (43 1)Re(2)-P(5)-C(511)Re(2)-P( 5)-C(52 1)Re(2)-P(5)-C(531)Re(2)-P(6)-C (6 1 1)Re (2)-P (6)-C (62 1)Re(2)-P(6)-C(631)C( 4 1 1 )-P( 4)-C (42 1)C( 42 1)-P( 4)-C(43 1)C (5 1 1 )-P( 5 ) s (52 1)C(521)-P(5)<(531)C(61 l)-P(6)-C(621)C(611)-P(6)-C( 631)C (62 1)-P( 6)-C (63 1)c(41 i)-P(4)-c(431)c(51 i)-P(5)-c(531)2.401 (6)2.4 98 (8)2.386( 8)1.73(2)1.24(3)1.84(2)1.84(2)1.83(2)1.87(2)1.84(2)1.87(2)1.82( 3)1.88(3)1.89(3)3.79(1)3.79( 1)3.2 8 (2)2.95(2)3.32(2)10 1.2 (2)143.0(3)101.6( 3)104.1(7)86.3 (8)106.2( 7)177(2)1 17.4( 7)122.3 (8)110.6(9)116.4(7)109.4(8)1 20.9 (8)115.4(10)1 1 7.9 (8)113.3(9)102(1)l O l ( 1 )101 (1)l O l ( 1 )103(1)104( 1)105( 1)l O l ( 1 )102(1)values for Re-P (see Experimental section), and, in part,t o different non-bonding contacts.The Re-N distances agree with corresponding valuesfor [ReBr,(NO) (HOEt)]- [1.723( 15) A] ,1 [ReBr,(NCMe)-(NO)]- [1.771(11) A]: and for a number of second- andl4 V.G. Albano, P. L. Bellon, and M. Sansoni, J. Chem. Soc.l5 G. R. Clark, B. W. Skelton, and T. N. Waters, Inorg. Chim.l6 P. Bird, J. F. Harrod, and K. A. Than, J. Amev. Chem. Soc.,(A), 1971, 2420.Acta, 1975, 12, 235.1974, 96, 1222.third-row transition-metal nitrosyls. The N-0 distancesare somewhat longer than usually found, but are notunique (see 1.24(3) A in [Ir(NO)(PPh,),] (ref. 14)). TheRe-N-0 interactions are essentially linear, establishingthe presence of NO+ ligands. The rather low v(N0)stretching frequency (at 1 640 cm-1) is, once more, notindicative of a bent metal-nitrosyl interaction, but isconsistent with the presence of long N-0 bond lengths.A possible explanation for the lengthening is that thetrans-hydrido-ligand makes the Re-N bond poorer in Qbut stronger in IC character, with a consequent decreasein N-0 bond-order.The main feature of the present structure determina-tion consists of the distorted co-ordination geometry ofthe [ReH,(NO)(PPh,)J molecule.Both the direct andindirect location of the hydrido-hydrogen atoms (seeExperimental section) are indicative of the fact that theseatoms lie in the plane containing Re, the NO group,and the P atom of the equatorial phosphine, with a H-Re-H angle in the range 90-100". The co-ordination of thefour equatorial ligands does not therefore show largedeviations from ideal octahedral geometry. A verylarge deviation consists of the bending of the two axialphosphines toward the hydrido-ligands, the P-Re-Pangle being 143.4(3) in molecule (I) and 143.0(3)' inmolecule (11). Distortions of the same kind have beenobserved in similar structures, due to the low sterichindrance of the hydrido-ligands. The P-M-P axialangle in mer-[IrH,( PPh,)J [ 153.0( 3) " j , l5 [ Ir (CO) H,-(PPh3)J+ [151.4(2)O],16 cis-[FeH,(PPh(OEt),),][136.7( 1) "1 ,17 and cis-[RuH,(PPh,),] [ 116.4(2) '1 18 de-creases according to the bulkiness of the various ligands.In particular, our value is ca. 8" smaller than that for[Ir(CO)H,(PPh,)J+ and seems to confirm that nitrosylnitrogen possesses a larger non-bonded radius than car-bony1 carbon in transition-metal c0mp1exes.l~The bonding parameters within the triphenylphosphineligands are unexceptional. The P-C bond lengths are inthe range 1.79-1.89 A, mean 1.84 A. The Re-P-C anglesexhibit the usual enlargement [means: 116.5 molecule (I)and 116.0" molecule (11)] with respect to the tetrahedralvalue; the C-P-C angles show a corresponding decrease[means: 101 molecule (I) and 102" molecule (TI)].We thank the Italian Consiglio Nazionale delle Ricerchefor support.[6/203 Received, 30th Janztauy, 197611' L. J. Guggenberger, D. D. Titus, M. T. Flood, R. E. Marsh,A. A. Orio, and H. B. Gray, J. Amer. Chem. Soc., 1972, 94, 1135.A. Immirzi and A. Lucherini, Cryst. Struct. Comm., 1972,1, 317.lS V. G. Albano, A. Araneo, P. L. Bellon, G. Ciani, and M.Manassero, J. Organometallic Chenz., 1974, 67, 314 and refs.therein
ISSN:1477-9226
DOI:10.1039/DT9760001943
出版商:RSC
年代:1976
数据来源: RSC