摘要:

AbstractThe Lewis acids RBH2are added to the basis B‐B bond of tri‐tert‐butylazadiboriridine, NB2tBu3(1a), to give 5‐alkyl‐1,2,3‐tri‐tert‐butyl‐1‐aza‐nido‐tetraboranes of type3(twoendo‐H atoms at B5) or type4(one H atom in a B2–B5 bridging position, oneexo‐H atom at B5), either as a mixture of3and4 (3, 4b–d: R  Me,tBu, CMe2iPr) or with the isomer4in high excess (4e, f: R  Ph,sBu). The reaction of dialkylboranes R2BH with1ayields 5,5‐dialkyl‐1,2,3‐tri‐tert‐butyl‐1‐aza‐nido‐tetraboranes of type4(one H atom in a B2‐B5 bridging position;4g, h: R2 Et2, cycloocta‐1,5‐diyl). In boiling THF, trialkylboranes BR3transform1ainto NB2tBu2R which, expectedly, dimerizes spontaneously to give a dialkyltetra‐tert‐butyl‐2,5‐diaza‐nido‐hexaborane of type2 (2a, b: R  Me, Et). The products of the addition of aminoboranes H2BNRR' to1aare identified as alkyl derivatives of 2,5‐diaza‐arachno‐pentaborane, N2B3tH2tBu3RR' (5a–d, R/R' = H/Pr, H/tBu, Me/Me, Et/Et). The aminoborane H2B  NiPr2with a sterically more demanding amino group hydroborates the B‐B bond of1ato give the acyclic productiPr2NBH‐B(tBu)‐N(tBu)B(tBu)H (6). In contrast to the B atoms, the N atoms in the electron‐deficient cluster skeletons of 2–5need not take part in (3c,2e) bo

ISSN:0009-2940    

DOI:10.1002/cber.19951280102

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractTreatment of Se(NSO)2with TeF4in CH2Cl2yields the compounds (4a) and (5b), while with TeBr4after six months (2d) is formed. An almost quantitative yield of Cl4Te2N4S2(6) is obtained from either Cl6Te2N2S (1a) and (CH3)3SiNSNSi(CH3)3in CH2Cl2at 20°C (2 d) or TeCl4and (CH3)3SiNSO (molar ratio 1:2) in CH2Cl2at 60°C (3 d). The use of (CH3)3SiOSi(CH3)3as solvent in the last mentioned procedure gives1aand small amounts of Cl2Te(NSO)2. Similarly, F2Te(NSO)2is prepared from TeF4and (CH3)3SiNSO in CH2Cl2. Dechlorination of1awith (C6H5)3Sb leads to (2a), which is also produced from TeCl4and [(CH3)3Si]2NSN[Si(CH3)3]2. When TeF4is used instead of TeCl4(molar ratio 3:1) the salt (7a) is formed. Similarly, (7b) is prepared from2aand AsF5or Ag+[AsF−6] in SO2. A new method for the preparation of bicyclic type1telluraheterocycles involves bromination of2ayielding Cl2Br4Te2N2S (1b). Dehalogenation with (C6H5)3Sb converts1binto (2b). When2bis treated with Br2in CH2Cl2an oxidative halogenation takes place with formation of Br6Te2N2S (1c). Metathetical exchange between2band Ag+[AsF−6] gives (7c). Isostructural S(NSO)2reacts with TeCl4for several weeks at 60°C in CH2Cl2to form S4N4. TeCl4and [S5N+5][Te3Cl−3], in contrast to the corresponding reaction with Se(NSO)2. The molecular structures of4a, 7b, 8, and [S5N+5][Te3Cl−13] have been determined by X‐ray diffraction methods. Spectroscopic data for all new compounds a

ISSN:0009-2940    

DOI:10.1002/cber.19951280103

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractWOCl4reacts at 200°C with tellurium in a sealed, evacuated ampoule with the formation of Te6(WOCl4)2. The structure consists of six‐membered tellurium rings in a boat conformation with significant transannular interactions and of pyramidal WOCl4units which are linked by linear asymmetric O...;WO bridges to polymeric (WOCl4)n, chains. The observed paramagnetism is consistent with the ionic formulation Te2+6[(WOCl−4)2]n. In the reaction of WCl6, I2and Te in a 2:1:6 ratio Te6I2(WCl6)2is formed at 150°C. The crystal structure consists of Te6I2+2cations and of slightly distorted octahedral WCl−6anions. The Te6I2+2ions are isostructural with Se6I2+2and consist of a six‐membered ring of Te atoms in the chair conformation with two I atoms bound in the 1,

ISSN:0009-2940    

DOI:10.1002/cber.19951280104

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractBy in situ lithiation of the trifunctional amines H3CC(CH2NHSiMe3)3, PhC(CH2NHSiMe3)3, and HC{SiMe2NH(p‐Tolyl)}3and subsequent reaction with SnCl2the corresponding triamidostannates were obtained. These were coupled with CpM(CO)2Cl (M  Fe, Ru) to yield the M—Sn‐bonded heterobimetallics9–14of which H3CC(CH2NSiMe3)3SnFe(CO)2Cp (9) was characterized by a single‐crystal X‐ray structure analysis. Of the in situ‐generated amidostannates only [HC{SiMe2N(p‐Tolyl)}3Sn][Li(THF)3] (8) could be isolated as a uniform product and characterized analytically and

ISSN:0009-2940    

DOI:10.1002/cber.19951280105

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe structures of cationic species of the series [X2YNYX2]+(X  F, Cl; Y  S, Se) have been computed ab initio using all electron treatments for first‐row elements and sulfur and quasi‐relativistic pseudopotentials for Se and Cl. Splitvalence basis sets with polarization and diffuse functions were employed. The MP2 results for the (non‐isostructural!) cations [Cl2SeNSeCl2]+(1:Cs) and [F2SNSF2]+(2:C2v) are in excellent agreement with the experimental (X‐ray) observations. Both structures represent local minima. A deeper minimum for either of the cations is represented by anotherC2visomer which for crystal lattice energy reasons is stable in the isolated state only. The geometries of the hitherto unknown species [Cl2SNSCl2]+(3) and [F2SeNSeF2]+(4) have been assessed by ab initio HF calculations. In analogy to2, cations3and4are predicted to preferC2vsymmetry. Therefore,1exhibits unusual structural features. According to strictly localized natural bond orbital analysis (NBO), the central nitrogen atoms in1and2possess two lone pairs of electrons (LP: one sp hybrid and one p orbital). The relatively short SeN and SN bond distances in1(1.741–1.760 Å) and2(1.551 Å) can best be attributed to LP(N)→s̀*(YX) negative hypercon

ISSN:0009-2940    

DOI:10.1002/cber.19951280106

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe five‐coordinate chloro(hydrido)‐ and hydrido(iodo)ruthenium(II) and ‐osmium(II) compounds [MHX(CO)(PiPr3)2] (1, 2, 6, 7) react with CS2to give the octahedral dithioformato complexes [MCl(CO)(PiPr3)2(η2‐S2CH)] (3, 4, 8, 9) in excellent yields. In the initial step, an addition of the heteroallene to the metal center occurs which is followed by insertion of CS2into the M—H bond. On treatment of the dichlororuthenium(II) derivative [RuCl2(CO)(PiPr3)2] (10), which is prepared from RuCl3· aq and PiPr3in methanol, with carbon disulfide insertion into one of the Ru—PiPr3bonds takes place to give the six‐coordinate ruthenium(II) complex12with zwitterion−S2CPiPr3+as a chelating ligand. While the reaction of [OsH(SPh)(CO)(PiPr3)2] (13) with MeSCN leads to addition of the thionitrile to the metal center, the starting material reacts with MeNCS by insertion of the heteroallene into the Os—SPh bond to give two stereoisomers15a, b, in which the nitrogen atom of the chelate ring is eithercisortransto the hydrido ligand. The octahedral methoxydithiocarbonato‐ and formatoosmium(II) compounds16and17are prepared from2and CS2or CO2in the presence of NaOMe. The crystal and molecular structures of4(M = Os),12and15

ISSN:0009-2940    

DOI:10.1002/cber.19951280107

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractVinylidene Transition‐Metal Complexes, XXXV[1]. — The Supporting Role of Phosphino Ester Ligands for the Synthesis of Neutral Carbene, Vinylidene and Allenylidene Ruthenium(II) ComplexesThe reaction of [RuCl2(PPh3)3] (1) with the phosphino estersiPr2P(CH2)nCO2R (2–4) leads to complete (n= 1; R  CH3, C2H5) or partial (n= 2; R CH3) displacement of the PPh3ligands and formation of the octahedral ruthenium(II) complexes [RuCl2{k2(P,O)‐iPr2PCH2CO2R}2] (5, 6) and [RuCl2(PPh3){k(P)‐iPr2PCH2CH2CO2Me}{k2(P,O)‐iPr2PCH2CH2CO2Me}] (7). Treatment of5with LiBr and LiI affords the dibromo‐ and diiodoruthenium derivatives8and9.While compound5reacts with CO and SO2by cleavage of one Ru—O bond to yield the 1:1 adducts [RuCl2(L){k(P)‐iPr2PCH2CO2Me}{k2(P,O)‐iPr2PCH2CO2Me}] (10, 11), the reaction of the dibromo derivative8with CO in solution gives the dicarbonyl complex [RuBr2(CO)2{k(P)‐iPr2PCH2CO2Me}2](13). If CO is passed over8in the solid state, the corresponding monocarbonyl compound14is formed. The hydridoruthenium(II) complex16, which is obtained from equimolar amounts of [RuHCl(CO)(PiPr3)2] (15) and2, reacts with HCCMe by insertion to give the vinyl derivative [RuCl{E—CHCHMe}(CO)(PiPr3){k2(P,O)‐iPr2CH2CO2Me}] (17). Treatment of5with HC̊' (R'  H, Me,tBu, Ph) and of6, 8, 9with HCCPh affords upon photochemical activation the octahedral vinylidene complexes [RuX2‐(CCHR){k(P)‐iPr2PCH2CO2R}{k2(P,O)‐iPr2PCH2CO2R}] (18–21and23–25) in good to excellent yield. At room temperature, these compounds (with the exception of25) are highly fluxional in solution. From31P‐NMR measurements, the free energies of activation ΔG‡for the intramolecular rearrangement have been determined. Whereas the reaction of 5 with HCČH2CH2OH leads to the carbene complex30containing the cyclic oxycarbene :C(CH2)3O as ligand, the functionalized vinylidene derivatives31and32are formed on treatment of5with aryl‐substituted alkynols HC≡RR'OH (R  Ph, R'  Ph,o‐Tol). These react in toluene solution at 80°C by elimination of water to give the allenylidene complexes [RuCl2(CCCRR'){k(P)‐iPr2PCH2CO2Me}{k2(P,O)‐iPr2PCH2CO2Me}] (33, 34). The X‐ray structure analysis of33reveals atransdisposition of the chloro ligands, the phosphorus atoms as well as of one CO oxygen and the α‐C atom of the allenylidene unit. Compound33reacts with CO, CNtBu and pyridine to give the 1:1 adducts [RuCl2(L)(CCCPh2){k(P)‐iPr2PCH2CO2Me}2] (35–37) and with HCl by attack on the central CC bond to yield the vinylcarbene complex [RuCl2(C(Cl)CHCRR'){k((P)‐iPr2‐PCH2CO2Me}{k2(P,O)‐iPr2PCH2CO2Me}] (38). The

ISSN:0009-2940    

DOI:10.1002/cber.19951280108

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractSynthesis and Complex Chemistry of Functionalised Tripod Ligands RC(CH2PPh2)3Malonic ester1is alkylated and converted into the triols RC(CH2OH)3(5). These are easily converted into the corresponding functionalised tripodal ligands RC(CH2PPh2)3(7) with R  Bzl (a),n‐C12H25(b), (CH3)2CH(CH2)2(c). Crystals suitable for X‐ray crystallography have been obtained of the ligand7a. In addition, the tripod ligands7aand7chave been further characterized by the syntheses and X‐ray analyses of the nickel complex [(7a)NiCl] (8a), the iron complex [(7c)Fe(NCCH3)3](BF4)2[9· (BF4)2], and the cobalt complex [(7c)Co{O(O)CCH3}](BPh4) (

ISSN:0009-2940    

DOI:10.1002/cber.19951280109

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractTransfer of acyclo‐E5Ligand (E  P, As) from an Iron to a Ruthenium and an Osmium Center☆The thermolysis of [Cp*Fe(η5‐E5)] (1) and [{Cp*M(CO)2}2] (2, 3) affords bycyclo‐E5transfer the sandwich complexes [Cp* M(η5‐E5)] (4a, b: M  Ru, E  P, As;4c: M  Os, E  P). The crystal‐structure analysis of [(C5Me4Et)Os(η5‐P5)] (4c') confirms i

ISSN:0009-2940    

DOI:10.1002/cber.19951280110

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractPolyol Metal Complexes, XII[1]. — Synthesis and Structure of Cobalt(III) Complexes with Doubly Deprotonated Anhydroerythritol, Methyl α‐DMannopyranoside, and Methyl α‐DGalactopyranosideThe polyols anhydroerythritol (AnEryt), methyl α‐D‐mannopyranoside (Me‐α‐D‐Manp), and methyl α‐D‐galactopyrano‐side (Me‐α‐DGalp) are deprotonated twice to form the cobalt(III) complexes [(en)2Co(AnErytH‐2)]I (1), δ‐[(en)2‐ Co(Me‐α‐DManp3,4H‐2)]ClO4· NaClO4· 2H2O (2), and δ‐[(en)2Co(Me‐α‐DGalp2,3H‐2)]ClO4·H2O (3), resp., in aqueous, alkaline solutions oftrans‐[(en)2CoCl2]Cl. The cryst

ISSN:0009-2940    

DOI:10.1002/cber.19951280111

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY