摘要:

AbstractDihydrobis(tetrazolyl)borate metal compounds of the composition [M(L)2{μ‐H2B(CHN4)2}2]nfor M = Mn, Fe, Co, Zn, Cd with L = H2O and for M = Cu with L = NH3are obtained from metal salts and K[H2B(CHN4)2]. Single‐crystal X‐ray studies reveal the formation of two‐dimensional rhombic grid sheets through the bridging action of the bis(tetrazolyl)borate ligands. Each metal atom is octahedrally coordinated with twotransL ligands and four H2B(CHN4) −2nitrogen donors. Two additional, hydrogen‐bonded water molecules occupy the rhombic openings in the compounds with M = Mn, Fe, Co, Zn, and Cd. The water of crystallization is held in place through hydrogen bonding from the water ligands and to the nitrogen atoms to give a substructure of parallel kinked water chains. Temperature‐variable magnetic measurements show a Curie‐Weiss behavior for the paramagnetic complexes with M =

ISSN:0009-2940    

DOI:10.1002/cber.19951280402

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA novel type of tripodal amido ligand with a totally siliconbased (trisilylsilane‐derived) ligand framework has been synthesized and coordinated to tetravalent titanium and zirconium. The key compound in the ligand synthesis is the chlorosilane H3CSi{Si(CH3)2CI}3(2) which upon condensation with a range of primary amines R‐NH2(R = aryl, alkyl) yields the amino‐functionalized ligand precursors H3CSi{Si(CH3)2NHR}3(3a–e). Their corresponding trilithium salts have been found to be the appropriate amide transfer reagents in the subsequent syntheses of the transition metal complexes. Single‐crystal X‐ray structure analyses of the trilithium triamide H3CSi{Si(CH3)2N(Li)tBu}3(4a) and the Ti complex H3CSi{Si(CH3)2N(p‐Tol)}3TiBr (5b) have established their respective adamantane‐ and [2.2.2]bicyclooctane‐relate

ISSN:0009-2940    

DOI:10.1002/cber.19951280403

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractTwo new types of bismuth(III) tropolonato complexes, nitratobis(tropolonato)bismuth(III) (1d) and phenylbis(tropolonato)bismuthin (1f), are synthesized and characterized by elemental analysis,1H‐NMR,13C‐NMR, IR spectroscopy, and conductivity measurements. The structures of1dand aquabis(4,5‐benzotropolonato)bismuth(III) nitrate (6b) are confirmed by X‐ray structural analyses. Derivatives of tropolone (2a) and their bismuth(III) complexes are synthesized and characterized in the same manner. Eight of these compounds are tested againstHelicobacter pylori(H.p.) bacteria, which cause chronic gastritis and peptic ulcus. Most of the bismuth compounds show high in vitro activity aga

ISSN:0009-2940    

DOI:10.1002/cber.19951280404

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractAlkynylpalladium compoundstrans‐PdX(CCR)(PMe3)2[R = CMe3, X = Cl (1), I (19); R = CMe2OH, X = Cl (2), Br (10), I (11); R =c‐Hex, X = Cl (3), Br (12), I (13); R = CHMe2, X = Br (4); R = CH2SiMe3, X = Cl (5), Br (14), I (15); R = COOEt, X = Br (6), I (7); R = Ph, X = Cl (8), I (17); R =n‐Pr, X = N3(16), I (20); R =n‐Hex, X = I (21); R = SiPh3, X = Br (22)] andtrans‐PdX(CCR)(PBu3)2[R = SiMe3, X = Cl (9), I (18)] as well astrans‐PdX(CCR)(PPh3)2[R = CMe3, X = Br (23); R = CH2SiMe3, X = Br (24), I (25)] are prepared by known methods. Thermal decomposition between 120 and 160°C results in a selective transformation only with trimethylphosphane complexes1, 2, 10–, and19. Oxidative trimerization of the alkynyl groups CCCMe2R′ and CC(c‐Hex) affording the enediynyl compoundstrans‐PdX[C(CCCMe2R′) = C(CCCMe2R′)CMe2R′] (PMe3)2[R′ = Me, X = Cl (26), I (27); R′ = OH, X = Cl (28), Br (29), I (30)] andtrans‐PdX{C[CC(c‐Hex)]C[CC(c‐Hex)] (c‐Hex)}(PMe3)2[X = Br (31), I (32)] appears to be controlled by balanced steric demands of phosphorus and alkynyl substituents. The steric control is investigated by melting) transformable monoalkynyl complextrans‐PdI(CCCMe2OH)(PMe3)2(11) with non‐transformable[*]complextrans‐PdI[CC(n‐Pr)](PMe3)2(20) to give a mixture (A) of transformed complexes with mixed substituents R. Similar results are obtained in other mixtures, when transformable PdBr(CCSiMe3)(PMe3)[1]is heated with the non‐transformable complexes PdBr[CC(n‐Pr)](PMe3)2[1]and20(mixtureB) o

ISSN:0009-2940    

DOI:10.1002/cber.19951280405

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe bis[(tert‐butyldimethylsilyl)amino]silanes1–3are converted into their lithium derivatives4–7with BuLi. Depending on the bulkiness of the substituents, the dilithium derivatives4and5crystallize incisortransconformation. Monolithiated3(6) forms a four‐membered (SiFLiN) ring system, while its dilithium salt is characterized as a lithium silyldiamide (7), Although4, 5, and7have different structures, they react with PF3(8, 9), SiF4(10, 11), and CMe3SiF3(12) as diamides to give the corresponding four‐membered ring systems8–12. The crystal structures of4and5a

ISSN:0009-2940    

DOI:10.1002/cber.19951280406

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractReaction of the 2,5‐hexanedione‐derived bisfulvene1with RLi reagents (R = phenyl orn‐butyl) yields the ring‐closed [4‐(cyclopentadienylidene)‐7‐R‐4,7‐dimethyl‐4,5,6,7‐tetrahydroindenyl]dilithium reagents3. Their reaction with MCl4(M = Ti, Zr, Hf) gives the corresponding ansa‐group‐4‐metallocene dichloride complexes4, 6, or7. In a similar way the [7‐allyl‐4‐(η‐cyclopentadienylidene)‐4,7‐dimethyl‐4,5,6,7‐tetrahydro‐η5‐indenyl]metal dihalides (M = Ti, Zr) (6d, 4d) are prepared. Two diastereomers are formed in most cases, some of which could be separated. The five representative examplescis‐ andtrans‐4c,trans‐4d,cis‐6c, andtrans‐7cof these complexes were characterized by X‐ray diffraction. All these six‐membered ring‐annulated C1‐bridged ansa‐metallocene dichlorides exhibit extremely small D1ZrD2 angles (D1 and D2 denote the centroids of the cyclopentadienyl rings) of 116.5°, i.e., they are characterized by a very open bite of the bent metallocene wedge. The homogeneous Ziegler‐type catalysts derived from these ansa‐zirconocenes by activation with methylalumoxane have high activitie

ISSN:0009-2940    

DOI:10.1002/cber.19951280407

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractHydrophosphorylation of 1,4‐bis(diphenylphosphanyl)butadiyne with diphenylphosphane leads to the butadiene (Ph2P)2CCHCHC(PPh2)2(1). Treatment of1with dimethylsulfonium methylide gives the vinylcyclopropane (Ph2P)2CCHCH(CH2)C(PPh2)2(2). Compound2reacts with aqueous hydrogen peroxide, elemental sulfur, or selenium to afford the tetrachalcogenides (Ph2XP)2CCHCH(CH2)C(PXPh2)2with X = O (3), X = S (4), X = Se (5), respectively. While the tetraphosphane1and the vinyl‐cyclopropane compound2cannot be converted into a bis‐(cyclopropyl) compound with an excess of Me2SCH2, the tetrasulfide4readily affords a mixture of (1R,1′R)‐/(1S,1′S)‐andmeso‐2,2,2′,2′‐tetrakis(diphenylthiophosphinyl)‐1,1′‐bicyclopropyl (6, 7) in good yield. Treatment of 1,1,4,4‐tetrakis‐(diphenylphosphanyl)butatriene with dimethylsulfonium methylide leads to the vinylidenecyclopropane (Ph2P)2CCC(CH2)C(PPh2)2(8). Compound8is converted into its tetrasulfide (Ph2SP)2CCC(CH2)C(PSPh2)2(9) by treatment with elemental sulfur. The crystal structures of1, 2, 4, 7, and8h

ISSN:0009-2940    

DOI:10.1002/cber.19951280408

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe cationic carbyne complexes [Cp(CO)2MCR]+[BX4]−[M = Mn, X = F: R = Ph (1), Tol (2); M = Re, X = 3,5‐C6H2(CF3)2: R = Ph (3)] add the anion of monodeprotonated protected mannofuranose (4a), glucofuranose (4b), and fructopyranose (4c) to the carbyne carbon atom to form the carbohydratocarbene complexes5a–c, 6a, b, and7a. With5b,5c, and6bthe addition proceeds with retention of configuration at the anomeric center. Due to inversion of configuration in the deprotonation step the complexes5a, 6a, and7aare obtained as β‐glycosides. The carbene ligand is oxidatively cleaved from the metal by trimethylamineN‐oxide or air. Cleavage of the C(carbene)O bond with reformation of the cation of the carbyne complex2is achieved by reaction of6awith BCl3. Photolysis of [Cp(CO)2MnC(Ph)OEt] in the presence of L affords the carbene complexes [Cp(CO)(L)MnC(Ph)OEt][L = P(OMe)3(11), P(Tol)3(12)]. Ethoxide abstraction from11and12by BF3gives the chiral cationic carbyne complexes [Cp(CO)(L)MnCPh]+[EF4]−(13,14) which add4ato form the corresponding mannofura‐nosylcarbene complexes (15, 16). When 0.5 equivalents of4aare employed in the reaction with13, 14the ratio of diastereomers is 3:2, both for15and16. Complex11was characterized by an X

ISSN:0009-2940    

DOI:10.1002/cber.19951280409

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

Ylidyl‐dihalophosphanes Provide Structural Snapshots on Their Way to DissociationThe reaction of phosphonium ylides with phosphorus trihalides has been studied for the synthesis of ylidyl‐dihalophos‐phanes (= dihalophosphanyl ylides) Ph3PCRPX23, X = Cl, and9, X = Br. Compounds3, R = aryl, are readily prepared from the phosphonium bromides [Ph3PCH2R]Br, compounds3, R = alkyl, SiMe3or PCl2, and9are obtained from silylylides Ph3PCRSiMe3, compound3, R = PPh3+results from the addition of PCl3to the hexaphenylcarbodiphosphorane. A (β‐morpholinovinyl)dichlorophosphane12has also been prepared. Ylides3are oxidized by sulfur and selenium and are converted to ylidyl‐chlorophosphenium (= chloro‐phosphaalkenyl‐phosphonium) salts [Ph3PCRPCl]AlCl410. In the31P‐NMR spectra of3and9the geminal coupling2JPPindicates the phosphorus lone pair to be synperiplanar to the phosphonio group. In one case the P(III)C rotation barrier has been estimated from VT‐31P‐NMR spectra. By X‐ray crystallography the structures of3, R = Me, 2,6‐Cl2C6H4, 4‐NO2C6H5, PCl2, of9, R = Me (two molecules), SiMe3, of an ylidyl‐selenophosphonyl dichloride (11b), and of12have been analyzed. They provide representatives for the full range of rotation from the symmetric conformer with two equal PX bonds to the conformer with one PX bond perpendicular to the PCP plane and with this bond being extremely elongated. Thus, they map out the pathway to PX bond breaking. On this way the initial charge transfer from the ylidic carbon to the antibonding PX

ISSN:0009-2940    

DOI:10.1002/cber.19951280410

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

Organometallic Compounds of the Lanthanoids, 89. – Cyclooctatetraenyl Complexes of the Early Transition Metals and Lanthanoids, 6. – (Cyclooctatetraenyl)[N,N′‐bis(trimethylsilyl)benzamidinato]‐ and ‐[diphenylbis(trimethylsilylimido)‐phosphinato]Complexes of the Rare Earths; X‐Ray Structural Analyses of (C8H8)Tm[PhC(NSiMe3)2](THF), (C8H8)Lu[4‐MeOC6H4C(NSiMe3)2](THF), and (C8H8)Nd[Ph2P(NSiMe3)2](THF)[(C8H8)Ln(μ‐Cl)(THF)2]2or [(C8H8)Ln(μ‐O3SCF3)(THF)2]2(Ln = Y, Ce, Pr, Nd, Sm, Tm, Lu) react with Na[4‐RC6H4C(NSiMe3)2] (R = H, OMe, CF3) or Li[PhC(NSiMe3)2] to give the monomeric (cyclooctatetraenyl)lanthanide benzamidinates (C8H8)Ln[4‐RC6H4C(NSiMe3)2](THF) [R = H, Ln = Y (1), Ce (4), Pr (6), Nd (8), Sm (10), Tm (12), Lu (15); R = OMe, Ln = Y (2), Ce (5), Pr (7), Nd (9), Sm (11), Tm (13), Lu (16); R = CF3, Ln = Y (3), Tm (14), Lu (17)]. The reaction of [(C8H8)Ln(μ‐Cl)(THF)2]2(Ln = Ce, Pr, Nd, Sm) with Li[Ph2P(NSiMe3)2] in THF leads directly tothe monomeric compounds (C8H8)Ln[Ph2P(NSiMe3)2](THF) [Ln = Ce (18), Pr (19), Nd (20), Sm (21)] in good yields. The1H‐,13C‐,31P‐ and29Si‐NMR and mass spectra of the new compounds as well as the molecular structures of12, 16, and20are discussed. The Raman spectra of the complexes1–3,

ISSN:0009-2940    

DOI:10.1002/cber.19951280411

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY