摘要:

AbstractZrBr4reacts with Te2Br in a sealed evacuated ampoule at 210°C in quantitative yield to afford (Te24⊕)(Zr2Br210⊖) as blueblack, moisture‐sensitive crystals. The crystal‐structure determination shows, that (Te4)(Zr2Br10) consists of planar, nearly square Te24⊕and Zr2Br210⊖ions, that form edge‐sharing double octahedra. Both ions possess crystallographic 2/m(C2h) symmetry. At temperatures above 250°C (Te4)(Zr2Br10) decomposes with cleavage of Te –Te bonds into (TeBr3⊕)(Zr2Br9⊖), which forms yellow, hygroscopic crystals. (TeBr3)(Zr2Br9) can also be obtained by the reaction of two equivalents of ZrBr4with TeBr4at 260°C. The crystal structure is built of Zr2Br9⊖ions, that form face‐sharing double octahedra, and of pyramidal TeBr3⊕ions. Each TeBr3⊕ion exhibits three Te – Br contacts to two different Zr2Br9⊖ions, resulting in a strongly deformed octahedral coordination for the Te atom. The Zr2Br9double octahedra and the TeCl6octahedra are connected by common ed

ISSN:0009-2940    

DOI:10.1002/cber.19911240402

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Cyclic Metal(IV)AmidesSynthesis and structure of cyclic amide complexes of quadrivalent titanium, vanadium, and chromium are described, and their electrochemical behavior is investigated by cyclic voltammetry. The novel amides of formula ML2{MTi, (3b); MV, (3c); MCr, (3d); L=[(CH3)3SiNCH2CH2NSi(CH3)3]} are formed by reaction of the halide adducts MCl3(THF)3with the dilithium salt Li2L with concomitant disproportionation. Formation of3dproceeds via the complex[3 d]⊖and requires additional oxidation with oxygen or iodine. An X‐ray crystalstructure determination of3breveals the titanium atom in strongly distorted tetrahedral environment with approximate symmetryD2d. The amide complexes3b–dare monomeric, thermally stable, and sublime readily without decomposition; they are very sensitive to water and soluble in all common organ

ISSN:0009-2940    

DOI:10.1002/cber.19911240403

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Synthesis of 1,2,5‐Azastannaborole Derivatives from Sulfur Diimide Anions andcis‐Stannyl‐boryl‐alkenes – X‐ray Crystallographic Study of Two 2,5‐Dihydro‐1‐(imino‐λ4‐sulfanylidene)‐1,2,5‐azastannaboratoles(E)‐3‐(Diethylboryl)‐2‐(chlorodimethylstannyl)‐2‐pentene (1) reacts with the sulfur diimide anions3[R – NSN−K+, R=tBu (a), Me3Si (b),tBu2P (c)] in a 1:1 ratio, and with4(K+;−NSN−K+) in a 2:1 ratio, to give various heterocycles. The first products of the reaction between1and3[2,5‐dihydro‐1‐(imino‐λ4‐sulfanylidene)‐1,2,5‐azastannaboratoles5a, b, c] are isolated at −30°C and characterized by X‐ray crystallography. The compounds5a,brearrange into the borole derivates6a,b(with an additional NSn coordination) by transfer of an ethyl group from the boron to the sulfur atom. Ethylene is eliminated from compound6a(not6b) to give the diaminosulfane derivative7a. The 2:1 reaction between1and4affords an unstable intermediate8with a fluxional structure, leading to9in which an EtS moiety bridges a borole ring (analogous to6but without the additional N – Sn coordination) and a boratole ring (analogous to5). All compounds are c

ISSN:0009-2940    

DOI:10.1002/cber.19911240404

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Stable Tellurium Ylides: Synthesis and Reactivity of Diorganyltelluronium 4,5‐Dicyanoimidazol‐2‐ylidesDiorganyl tellurides R2Te (RMe, Me3SiCH2, Ph) react with 2‐diazo‐4,5‐dicyano‐2H‐imidazole (1) at – 30°C to form the title compounds2– 4. The ylides3and4are thermally stable up to their melting points of 159 and 243°C, resp., whereas2undergoes a modified Stevens rearrangement at 190°C with formation of a 2‐(methyltelluro)imidazole (10). The reactivity of2–4is determined by an extreme charge separation between the onium centre and the ylide entity. No Wittig reactivity is observed, alkylation occurs at the imidazole nitrogen and carbanions lead to tetraorganyl tellurium comp

ISSN:0009-2940    

DOI:10.1002/cber.19911240405

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Reaction of [(Mes)Os(CO)Cl2] (3) with PhLi in benzene gives the diphenylosmium compound [(Mes)OsPh2(CO)] (6) whereas with PhMgBr [(Mes)OsPh(CO)Br] (7) is obtained. Treatment of3with TolMgBr in benzene or ether affords almost exclusively the monoaryl complex [(Mes)OsTol(CO)Br] (8). Compound3reacts with C6H11MgCl to give both [(Mes)Os(C6H11)2(CO)] (9) and [(Mes)Os(C6H10)(CO)] (10) in 60 and 30% yield, respectively. With C6H11MgBr, complex10is mainly obtained. Reaction of7and8with Na/Hg in THF/EtOH gives nearly quantitatively the arylhydridoosmium complexes [(Mes)Os‐C6H4R(CO)H] (14,15). The analogous hydrido methyl compound [(Mes)OsCH3(CO)H] (13) reacts with CCl4to produce [(Mes)OsCH3(CO)Cl] (17), which is not accessible from3and LiCH3or CH3MgX. The X‐ray structure analysis of10reveals that the cyclohexene is coordinated in theendoconfigurat

ISSN:0009-2940    

DOI:10.1002/cber.19911240406

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Metal Complexes of Biologically Important Ligands, LVII. – 1‐Selenoglucose as Ligand in Metal ComplexesReactions of the in situ‐prepared anion of acetylated 1‐selenoglucose with chloro complexes give the compounds R'3PAuSeR (R'=Me, El, Ph),cis;‐(Ph3P)2Pt(SeR)2and (η5C5H5)2Ti(SeR)2(SeR=2,3,4,6‐tetra‐O‐acetyl‐1‐seleno‐β‐D‐glucopyranosato‐Se). The complexes (η5‐C5H5)(OC)2FeSeR and (OC)3M(μ‐SeR)2M(CO)3(MFe, Ru) are prepared by the reaction of the diselenide RSeSeR with the dinuclear compound [η5‐C5H5Fe(CO

ISSN:0009-2940    

DOI:10.1002/cber.19911240407

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

d8Iron Nitrosylhydride ComplexesThe nitrogen complex [(OC)2(Et3P)2Fe]2N2(1) reacts with carboxylic acids to form the complexes (OC)2(Et3P)2Fe(H)OC(O)R [R=4‐methoxyphenyl,2a; R=2,4‐dimethoxyphenyl,2b; R=2,4,6‐trimethoxyphenyl,2c; R – Ph,2d; R – CF3, 2e]. Treatment of2withN‐methyl‐N‐nitroso‐p‐tolylsulfonamide produces the nitrosylcarboxylato complexes (OC)(ON)‐(Et3P)2FeOC(O)R (3a–d) in addition to the side product Fe(NO)2(PEt3)2(4) except for2ewhich forms4exclusively. Reaction of3with LiAlH4yields the hydridonitrosyliron complex (OC)(ON)(Et3P)2FeH (5a). A different synthetic route to the phosphorus donor‐substituted iron hydride complexes involves starting material (OC)2(L)2FeCl2[LPEt3,6a; L – PMe3,6b; LP(OiPr)3,6c]. Compounds6react withtBuLi and NOBF4to form (OC)(ON)L2FeCl (7). Subsequent treatment with NaBH4gives (OC)(ON)(L)2FeH [LPEt3,5a; LPMe3,5b; LP(OiPr)3,5c]. The structures of5band7aar

ISSN:0009-2940    

DOI:10.1002/cber.19911240408

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Transition‐Metal‐Substituted Diphosphenes, XXIII. ‐Studies on the Synthesis and Reactivity of Dihalophosphido Complexes of Iron and Ruthenium(η5‐C5Me5)(CO)2FeP(SiMe3)2(1a) reacts with two equivalents of C2Cl6to give the dichlorophosphido complex (η5‐C5Me5)‐(CO)2FePCl2(2a). The latter is easily converted into (η5‐C5Me5)(CO)2FeP(E)Cl2(3; ES;4: ESe) by treatment with the respective chalcogen. The reaction of1awith2aleads to a mixture of the cyclotriphosphane [(η5‐C5Me5)‐(CO)2FeP]3(8a) and the bicyclo[1.1.0]tetraphosphane [(η5‐C5Me5)(CO)2FeP)2P2(10). The same result is obtained when1ais treated with only one equivalent of C2Cl6. In addition the dihalophosphido complexes (η5‐C5Me5)(CO)2RuPCl2(2c), (η5‐C5H5)(CO)(PPh3)FePCl2(2b), (η5‐C5Me5)(CO)2FePBr2(2d), and (η5‐C5Me5)(CO)2FePI2(2e), and the cyclotriphos

ISSN:0009-2940    

DOI:10.1002/cber.19911240409

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractReactions of [(η5‐C5H5)Re(NO)(PPh3)(ClC6H5)]+BF−4and (n= 5,a; 6,b; 7,c; 8,d) give cycloalkene complexes (6a–d, 94 to 79%). A crystal structure of the methylcyclopentadienyl analog of6ashows the Re – plane and Re – PPh3bond to be coplanar, with the vinyl protonssynto the cyclopentadienyl ligand. Reaction of6aandtBuO−K+leads to the vinyl complex (9a, 90%) instead of expected allyl complex (10a) Analogous reactions of6b–dgive varying mixtures of9b–d/10b–d. HBF4· OEt2and9areact to form the cyclopentylidene complex (10+BF−4, 96%), the stability of which precludes any intermediacy in the deprotonation of6a. A crystal structure of11+PF−6shows the ReCC planes to be perpendicular to the Re – P bond. Spectroscopic features of compounds6are analyzed in detail, and NMR data show a high barrier to cyclopentylidene ligand rotation in11+BF

ISSN:0009-2940    

DOI:10.1002/cber.19911240410

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Transition‐Metal Stannyl Complexes, 3. – Metal, Hydrogen, Tin Three‐Center Bonding in Group VI Hydrido Stannyl ComplexesThe hydrido stannyl complex (π‐1,3,5‐Me3C6H3)(CO)2Cr(H)‐SnPh3(1) is prepared by photochemical reaction of (π‐1,3,5‐Me3C6H3)(CO)3Cr with HSnPh3. The119SnHCr coupling constant (327.6 Hz) and an X‐ray structure analysis [Sn – H 202(4), Cr – H 159(4), Cr – Sn 270.16(6) pm] show that the Sn – H bond is coordinated in an η2fashion. The complexes (CO)4(R3P)‐W(H)SnPh3(R3PPh3P, MePh2P) (2) and (CO)3(dppe)M(H)‐SnR3(MCr, SnR3=SnPh3; MMo, SnR3=SnMe3, SnPh3; MW, SnR3=SnMe3, SnPh2Me, SnPh3) (4–6) are obtained either by thermal reaction of (CO)4(R3P)W(THF) or (CO)3(dppe)ML (LTHF, acetone) with HSiR3, or by photochemical reaction of (CO)4(dppe)M with HSnPh3. Reaction of (CO)4(Ph3P)W(THF) with HSnMe3yields (CO)4(Ph3P)W(Sn‐Me3)2(3). The Sn,M,H coupling constants in the complexes2and (CO)3(dppe)M(H)SnR3(MCr, Mo) are in the range of 250 – 315 Hz and therefore these complexes seem to contain an η2‐coordinated stannane. Contrary to this, the SnWH coupling constants in (CO)3(dppe)W(H)SnR3are considerably lower (70 – 90 Hz), suggesting complete oxidative addition of the H – Sn bond. The complexes (CO)3(dppe)M(H)SnPh3decompose in benzene solution at room temperature to give, inter alia, hexaphenyldistannane. Ph6Sn2· 2 C6H6crystallizes in the space group\documentclass{article}\pagestyle{empty}\begin{document}$ R\bar 3 $\end{document}(Z=1); in the crystal lattice the benzene molecules are perpendicular to

ISSN:0009-2940    

DOI:10.1002/cber.19911240411

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY