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1.
Hui‐Xian Yeong Dr. Hong‐Wei Xi Dr. Yongxin Li Prof. Dr. Kok Hwa Lim Dr. Cheuk‐Wai So 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(35):11786-11790
The synthesis and reactivity of a silyliumylidene cation stabilized by an amidinate ligand and 4‐dimethylaminopyridine (DMAP) are described. The reaction of the amidinate silicon(I) dimer [ L Si:]2 ( 1 ; L =PhC(NtBu)2) with one equivalent of N‐trimethylsilyl‐4‐dimethylaminopyridinium triflate [4‐NMe2C5H4NSiMe3]OTf and two equivalents of DMAP in THF afforded [ L Si(DMAP)]OTf ( 2 ). The ambiphilic character of 2 is demonstrated from its reactivity. Treatment of 2 with 1 in THF afforded the disilylenylsilylium triflate [ L′ 2( L )Si]OTf ( 3 ; L′ = L Si:) with the displacement of DMAP. The reaction of 2 with [K{HB(iBu)3}] and elemental sulfur in THF afforded the silylsilylene [ L SiSi(H){(NtBu)2C(H)Ph}] ( 4 ) and the base‐stabilized silanethionium triflate [ L Si(S)DMAP]OTf ( 5 ), respectively. Compounds 2 , 3 , and 5 have been characterized by X‐ray crystallography. 相似文献
2.
Hui‐Xian Yeong Shu‐Hua Zhang Dr. Hong‐Wei Xi Dr. Jing‐Dong Guo Prof. Dr. Kok Hwa Lim Prof. Dr. Shigeru Nagase Prof. Dr. Cheuk‐Wai So 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(9):2685-2691
The synthesis and characterization of new amidinate‐stabilized germatrisilacyclobutadiene ylides [L3Si3GeL′] (L=PhC(NtBu)2; L′=ËL; Ë=Ge ( 3 ), Si ( 7 )) are described. Compound 3 was prepared by the reaction of [LSi? SiL] ( 1 ) with one equivalent of [LGe? GeL] ( 2 ) in THF. Compound 7 was synthesized by the reaction of 2 with excess 1 in THF. The bisamidinate germylene [L2Ge:] ( 4 ) is a by‐product in both reactions. Moreover, compound 7 was prepared by the reaction of 3 with one equivalent of 1 in THF. Compounds 3 and 7 have been characterized by NMR spectroscopy, X‐ray crystallography, and theoretical studies. The results show that compounds 3 and 7 are not antiaromatic. The puckered Si3Ge four‐membered rings in 3 and 7 have a ylide structure, which is stabilized by amidinate ligands and the electron delocalization within the Si3Ge four‐membered ring. 相似文献
3.
Yu‐Liang Shan Dr. Wai‐Leung Yim Dr. Cheuk‐Wai So 《Angewandte Chemie (International ed. in English)》2014,53(48):13155-13158
The synthesis of an N‐heterocyclic silylene‐stabilized digermanium(0) complex is described. The reaction of the amidinate‐stabilized silicon(II) amide [LSiN(SiMe3)2] ( 1 ; L=PhC(NtBu)2) with GeCl2?dioxane in toluene afforded the SiII–GeII adduct [L{(Me3Si)2N}Si→GeCl2] ( 2 ). Reaction of the adduct with two equivalents of KC8 in toluene at room temperature afforded the N‐heterocyclic carbene silylene‐stabilized digermanium(0) complex [L{(Me3Si)2N}Si→ Ge?Ge←Si{N(SiMe3)2}L] ( 3 ). X‐ray crystallography and theoretical studies show conclusively that the N‐heterocyclic silylenes stabilize the singlet digermanium(0) moiety by a weak synergic donor–acceptor interaction. 相似文献
4.
Tetrakis(di-tert-butylmethylsilyl)tetragermacyclobutadiene]ruthenium tricarbonyl [η4-(But 2MeSi)4Ge4]Ru(CO)3 is synthesized. This analogue of well-known cyclobutadiene transition metal complexes bears a tetragermacyclobutadiene derivative as ligand. The structure and spectroscopic parameters of the complex are compared with those of its iron-containing analogue [η4-(But 2MeSi)4Ge4]Fe(CO)3. Based on experimental data and results of quantum chemical calculations, it is shown that the π-donating ability of ligands increases upon replacement of carbon atoms in the cyclobutadiene moiety by silicon or germanium atoms, tetrasilacyclobutadiene and tetragermacyclobutadiene being comparable in π-donating activity. 相似文献
5.
Shi‐Meng Wang Xiao‐Yan Wang Prof. Dr. Hua‐Li Qin Prof. Dr. Cheng‐Pan Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6542-6546
A Pd‐catalyzed Suzuki cross‐coupling of arylboronic acids with Yagupolskii–Umemoto reagents was explored. In contrary to trifluoromethylations, the Pd‐catalyzed reaction of R?B(OH)2 and [Ar2SCF3]+[OTf]? provided the arylation products (R?Ar) in good to high yields. The reaction confirms that the S?Ar bonds of [Ar2SCF3]+[OTf]? can be readily cleaved in the presence of Pd complexes. The relatively electron‐poor aryl groups of asymmetric [Ar1Ar2SCF3]+[OTf]? salts are more favorably transferred compared to the electron‐rich ones. This reaction represents the first report of utilization of [Ar2SCF3]+[OTf]? as arylation reagents in organic synthesis. 相似文献
6.
Dr. Shenglai Yao Dr. Yun Xiong Dr. Tibor Szilvási Prof. Dr. Hansjörg Grützmacher Prof. Dr. Matthias Driess 《Angewandte Chemie (International ed. in English)》2016,55(15):4781-4785
The first 4π‐electron resonance‐stabilized 1,3‐digerma‐2,4‐diphosphacyclobutadiene [LH2Ge2P2] 4 (LH=CH[CHNDipp]2 Dipp=2,6‐iPr2C6H3) with four‐coordinate germanium supported by a β‐diketiminate ligand and two‐coordinate phosphorus atoms has been synthesized from the unprecedented phosphaketenyl‐functionalized N‐heterocyclic germylene [LHGe‐P=C=O] 2 a prepared by salt‐metathesis reaction of sodium phosphaethynolate (P≡C?ONa) with the corresponding chlorogermylene [LHGeCl] 1 a . Under UV/Vis light irradiation at ambient temperature, release of CO from the P=C=O group of 2 a leads to the elusive germanium–phosphorus triply bonded species [LHGe≡P] 3 a , which dimerizes spontaneously to yield black crystals of 4 as isolable product in 67 % yield. Notably, release of CO from the bulkier substituted [LtBuGe‐P=C=O] 2 b (LtBu=CH[C(tBu)N‐Dipp]2) furnishes, under concomitant extrusion of the diimine [Dipp‐NC(tBu)]2, the bis‐N,P‐heterocyclic germylene [DippNC(tBu)C(H)PGe]2 5 . 相似文献
7.
Dennis H. Mayo Yang Peng Peter Zavalij Kit H. Bowen Bryan W. Eichhorn 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(10):1120-1123
The disproportionation of AlCl(THF)n (THF is tetrahydrofuran) in the presence of lithium amidinate species gives aluminium(III) amidinate complexes with partial or full chloride substitution. Three aluminium amidinate complexes formed during the reaction between aluminium monochloride and lithium amidinates are presented. The homoleptic complex tris(N,N′‐diisopropylbenzimidamido)aluminium(III), [Al(C13H19N2)3] or Al{PhC[N(i‐Pr)]2}3, (I), crystallizes from the same solution as the heteroleptic complex chloridobis(N,N′‐diisopropylbenzimidamido)aluminium(III), [Al(C13H19N2)2Cl] or Al{PhC[N(i‐Pr)]2}2Cl, (II). Both have two crystallographically independent molecules per asymmetric unit (Z′ = 2) and (I) shows disorder in four of its N(i‐Pr) groups. Changing the ligand substituent to the bulkier cyclohexyl allows the isolation of the partial THF solvate chloridobis(N,N′‐dicyclohexylbenzimidamido)aluminium(III) tetrahydrofuran 0.675‐solvate, [Al(C19H27N2)2Cl]·0.675C4H8O or Al[PhC(NCy)2]2Cl·0.675THF, (III). Despite having a twofold rotation axis running through its Al and Cl atoms, (III) has a similar molecular structure to that of (II). 相似文献
8.
Peter B. Hitchcock Alexei V. Khvostov Michael F. Lappert Andrey V. Protchenko 《无机化学与普通化学杂志》2008,634(8):1373-1377
The potassium dihydrotriazinide K(LPh,tBu) ( 1 ) was obtained by a metal exchange route from [Li(LPh,tBu)(THF)3] and KOtBu (LPh,tBu = [N{C(Ph)=N}2C(tBu)Ph]). Reaction of 1 with 1 or 0.5 equivalents of SmI2(thf)2 yielded the monosubstituted SmII complex [Sm(LPh,tBu)I(THF)4] ( 2 ) or the disubstituted [Sm(LPh,tBu)2(THF)2] ( 3 ), respectively. Attempted synthesis of a heteroleptic SmII amido‐alkyl complex by the reaction of 2 with KCH2Ph produced compound 3 due to ligand redistribution. The YbII bis(dihydrotriazinide) [Yb(LPh,tBu)2(THF)2] ( 4 ) was isolated from the 1:1 reaction of YbI2(THF)2 and 1 . Molecular structures of the crystalline compounds 2 , 3· 2C6H6 and 4· PhMe were determined by X‐ray crystallography. 相似文献
9.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(26):7573-7577
A facile, one‐pot synthesis of [Na(OC≡As)(dioxane)x ] (x =2.3–3.3) in 78 % yield is reported through the reaction of arsine gas with dimethylcarbonate in the presence of NaOt Bu and 1,4‐dioxane. It has been employed for the synthesis of the first arsaketenyl‐functionalized germylene [LGeAsCO] ( 2 , L=CH[CMeN(Dipp)]2; Dipp=2,6‐i Pr2C6H3) from the reaction with LGeCl ( 1 ). Upon exposure to ambient light, 2 undergoes CO elimination to form the 1,3‐digerma‐2,4‐diarsacyclobutadiene [L2Ge2As2] ( 3 ), which contains a symmetric Ge2As2 ring with ylide‐like Ge=As bonds. Remarkably, the CO ligand located at the arsenic center of 2 can be exchanged with PPh3 or an N‐heterocyclic carbene i PrNHC donor (i PrNHC=1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) to afford the novel germylidenylarsinidene complexes [LGe‐AsPPh3] ( 4 ) and [LGe‐As(i PrNHC)] ( 5 ), respectively, demonstrating transition‐metal‐like ligand substitution at the arsinidene‐like As atom. The formation of 2 – 5 and their electronic structures have been studied by DFT calculations. 相似文献
10.
Dominik Vítek Prof. Aleš Růžička Lise Vermeersch Dr. Libor Dostál Dr. Jan Turek Prof. Roman Jambor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(70):e202202639
Reactivity studies of the GeII→B complex L(Cl)Ge⋅BH3 ( 1 ; L=2-Et2NCH2-4,6-tBu2-C6H2) were performed to determine the effect on the GeII→B donation. N-coordinated compounds L(OtBu)Ge⋅BH3 ( 2 ) and [LGe⋅BH3]2 ( 3 ) were prepared. The possible tuning of the GeII→B interaction was proved experimentally, yielding compounds 1-PPh2-8-(LGe)-C10H6 ( 4 ) and L(Cl)Ge⋅GaCl3 ( 5 ) without a GeII→B interaction. In 5 , an unprecedented GeII→Ga coordination was revealed. The experimental results were complemented by a theoretical study focusing on the bonding in 1 − 5 . The different strength of the GeII→E (E=B, Ga) donation was evaluated by using energy decomposition analysis. The basicity of different L(X)Ge groups through proton affinity is also assessed. 相似文献
11.
Tamara Eisenmann Jayaprakash Khanderi Stephan Schulz Prof. Dr. Ulrich Flörke 《无机化学与普通化学杂志》2008,634(3):507-513
Reactions of ZnX2 (X = Cl, Br) with equimolar amounts of Li[t‐BuC(NR)2] (R = i‐Pr, Cy) yielded mono‐amidinate complexes [{t‐BuC(NR)2}ZnX]2 (X = Cl, R = i‐Pr 1 , Cy 2 ; X = Br, R = i‐Pr 3 , Cy 4 ), whereas reactions with two equivalents of Li‐amidinate resulted in the formation of the corresponding bis‐amidinate complexes [t‐BuC(NR)2]2Zn (R = i‐Pr 5 , Cy 6 ). 1 ‐ 6 were characterized by elemental analyses, IR, mass and multinuclear NMR spectroscopy (1H, 13C), and single crystal X‐ray analysis ( 1 , 2 , 3 , 6 ). In addition, the single crystal X‐ray structure of [t‐BuC(NCy)2]ZnBr·LiBr(OEt2)2 7 , which was obtained as a byproduct in low yield from re‐crystallization experiments of 4 in Et2O, is reported. 相似文献
12.
《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(1):101-111
Treatment of titanyl sulfate in about 60 mM sulfuric acid with NaLOEt (LOEt?=[(η5‐C5H5)Co{P(O)(OEt)2}3]?) afforded the μ‐sulfato complex [(LOEtTi)2(μ‐O)2(μ‐SO4)] ( 2 ). In more concentrated sulfuric acid (>1 M ), the same reaction yielded the di‐μ‐sulfato complex [(LOEtTi)2(μ‐O)(μ‐SO4)2] ( 3 ). Reaction of 2 with HOTf (OTf=triflate, CF3SO3) gave the tris(triflato) complex [LOEtTi(OTf)3] ( 4 ), whereas treatment of 2 with Ag(OTf) in CH2Cl2 afforded the sulfato‐capped trinuclear complex [{(LOEt)3Ti3(μ‐O)3}(μ3‐SO4){Ag(OTf)}][OTf] ( 5 ), in which the Ag(OTf) moiety binds to a μ‐oxo group in the Ti3(μ‐O)3 core. Reaction of 2 in H2O with Ba(NO3)2 afforded the tetranuclear complex (LOEt)4Ti4(μ‐O)6 ( 6 ). Treatment of 2 with [{Rh(cod)Cl}2] (cod=1,5‐cyclooctadiene), [Re(CO)5Cl], and [Ru(tBu2bpy)(PPh3)2Cl2] (tBu2bpy=4,4′‐di‐tert‐butyl‐2,2′‐dipyridyl) in the presence of Ag(OTf) afforded the heterometallic complexes [(LOEt)2Ti2(O)2(SO4){Rh(cod)}2][OTf]2 ( 7 ), [(LOEt)2Ti(O)2(SO4){Re(CO)3}][OTf] ( 8 ), and [{(LOEt)2Ti2(μ‐O)}(μ3‐SO4)(μ‐O)2{Ru(PPh3)(tBu2bpy)}][OTf]2 ( 9 ), respectively. Complex 9 is paramagnetic with a measured magnetic moment of about 2.4 μB. Treatment of zirconyl nitrate with NaLOEt in 3.5 M sulfuric acid afforded [(LOEt)2Zr(NO3)][LOEtZr(SO4)(NO3)] ( 10 ). Reaction of ZrCl4 in 1.8 M sulfuric acid with NaLOEt in the presence Na2SO4 gave the μ‐sulfato‐bridged complex [LOEtZr(SO4)(H2O)]2(μ‐SO4) ( 11 ). Treatment of 11 with triflic acid afforded [(LOEt)2Zr][OTf]2 ( 12 ), whereas reaction of 11 with Ag(OTf) afforded a mixture of 12 and trinuclear [{LOEtZr(SO4)(H2O)}3(μ3‐SO4)][OTf] ( 13 ). The ZrIV triflato complex [LOEtZr(OTf)3] ( 14 ) was prepared by reaction of LOEtZrF3 with Me3SiOTf. Complexes 4 and 14 can catalyze the Diels–Alder reaction of 1,3‐cyclohexadiene with acrolein in good selectivity. Complexes 2 – 5 , 9 – 11 , and 13 have been characterized by X‐ray crystallography. 相似文献
13.
A series of zwitterionic aluminum complexes of the type AlX[(2‐O‐3,5‐tBu2C6H2)3PZ] (AlX [O3PZ]; X = Cl, Me, Et, and iBu; Z = H, Me) containing C3‐symmetric, formally dianionic, facially tridentate ligands [O3PZ]2? were prepared and structurally characterized. Although serendipitous, these complexes can be readily synthesized by partial protonolysis of AlX3 with equal molar (2‐HO‐3,5‐tBu2C6H2)3P (H3[O3P]) or [(2‐HO‐3,5‐tBu2C6H2)3p.m.e](OTf) ({H3[O3PMe]}OTf) in THF at 25°C or elevated temperatures. Alcoholysis of AlMe[O3PMe] ( 2 ) with an excess amount of MeOH in refluxing toluene generates AlOMe[O3PMe] ( 10 ). Salt metathesis of AlCl[O3PMe] ( 6 ) with nBuM (M = Li, MgCl) and NaOR (R = tBu, Ph) in ethereal solutions affords AlnBu[O3PMe] ( 9 ) and AlOR[O3PMe] (R = tBu ( 11 ), Ph ( 12 )), respectively. Reactivity of 10 , 11 , and 12 with respect to catalytic ring‐opening polymerization of ε‐caprolactone is assessed. 相似文献
14.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(15):4397-4400
The first zwitterionic borata‐bis(NHC)‐stabilized phosphaketenyl germyliumylidene [(L2(O=C=P)Ge:] 2 (L2=(p ‐tolyl)2B[1‐(1‐adamantyl)‐3‐yl‐2‐ylidene]2) has been synthesized by salt‐metathesis reaction of [L2(Cl)Ge:] 1 with sodium phosphaethynolate [(dioxane)n NaOCP]. Unexpectedly, its exposure to UV light affords, after reductive elimination of the entire PCO group, the unprecedented [L2Ge‐GeL2] complex 3 in 54 % yields bearing the Ge22+ ion with Ge in the oxidation state +1. In addition, the 1,3‐digermylium‐2,4‐diphosphacyclobutadiene [L2Ge(μ‐P)2GeL2] 4 and bis(germyliumylidenyl)‐substituted diphosphene [(L2Ge‐P=P‐GeL2)] 5 could also be obtained in moderate yields. The formation of 3 – 5 and their electronic structures have been elucidated with DFT calculations. 相似文献
15.
Katherine B. Aubrecht Karen Chang Marc A. Hillmyer William B. Tolman 《Journal of polymer science. Part A, Polymer chemistry》2001,39(2):284-293
In quest of new, single‐site catalysts for cyclic ester polymerizations, a series of mononuclear yttrium(III) complexes of N,N′‐bis(trimethylsilyl)benzamidinate ([LTMS]−) and hindered N,N′‐bis‐(2,6‐dialkylaryl)toluamidinates ([LEt]−, aryl = Et2C6H3, and [LiPr]−, aryl = iPr2C6H3) were synthesized and characterized by X‐ray diffraction: LY(μ‐Cl)2Li(TMEDA) ( 1 ), LY(OC6H2tBu2Me) ( 2 ), LY(OC6H3Me2)2Li(THF)4 ( 3 ), LY(μ‐OtBu)2Li(THF) ( 4 ), LiPrY[N(SiMe2H)2]2(THF) ( 5 ), LY(THF)(Cl)(μ‐Cl)Li(THF)3 ( 6 ), and LY[N(SiMe2H)2] ( 7 ). Coordination numbers ranging from five to seven were observed, and they appeared to be controlled by the steric bulk of the supporting amidinate and alkoxide, phenoxide, or amide coligands. Complexes 2 – 5 and 7 are active catalysts for the polymerization of D,L ‐lactide (e.g., with 2 and added benzyl alcohol, 1000 equiv of D,L ‐lactide were polymerized at room temperature in less than 1 h, with polydispersities less than 1.5). The neutral complexes 2 , 5 , and 7 were more effective than the anionic complexes 3 and 4 . In addition, the presence of the more hindered amidinate ligands [LEt]− and [LiPr]− on yttrium‐amides slowed the polymerizations ( 7 < 5 < Y[N(SiMe2H)2]3). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 284–293, 2001 相似文献
16.
Matthias Westerhausen Christin Birg Mathias Krofta Peter Mayer Thomas Seifert Heinrich Nth Arno Pfitzner Tom Nilges Hans‐Jrg Deiseroth 《无机化学与普通化学杂志》2000,626(5):1073-1080
Synthesis and Structures of Sr6P8 Polyhedra in Mixed Phosphanides/Phosphandiides of Strontium The strontiation of H2PSiiPr3 ( 1 ) with (THF)2Sr[N(SiMe3)2]2 in THF yields colorless tetrakis(tetrahydrofuran‐O)strontium bis(triisopropylsilylphosphanide) ( 3 ). The central alkaline earth metal atom has an octahedral environment with the phosphanide ligands in trans position. The homometalation in toluene leads to the elimination of 1 and THF. Cooling of this solution gives crystals of colorless tetrakis(tetrahydrofuran‐O)hexastrontium‐tetrakis(triisopropylsilylphosphanide)‐tetrakis(triisopropylsilylphosphandiide) ( 4 ). The equimolar reaction of H2PSitBu3 ( 2 ) with (THF)2Sr[N(SiMe3)2]2 in toluene yields in the first step heteroleptic dimeric {(Me3Si)2NSr(THF)2[P(H)SitBu3]}2 ( 5 )2. This compounds monomerizes in THF to (Me3Si)2N–Sr(THF)4[P(H)SitBu3] ( 6 ), which forms an equilibrium with the homoleptic dismutation products (THF)2Sr[N(SiMe3)2]2 and (THF)4Sr[P(H)SitBu3]2 ( 7 ). Compound ( 5 )2 undergoes a intramolecular strontiation and bis(tetrahydrofuran‐O)hexastrontium‐tetrakis[tri(tert‐butyl)silylphosphanide]‐tetrakis[tri(tert‐butyl)silylphosphandiide] ( 8 ) is isolated. The central Sr6P8‐polyhedra of 4 and 8 are very similar. 相似文献
17.
Christoph Wallach Dr. Felix S. Geitner Dr. Wilhelm Klein Prof. Dr. Thomas F. Fässler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(53):12349-12356
The synthetic approach towards molecules that contain Ge atoms with oxidation state 0, and which are exclusively connected to other Ge atoms, is explored by using anionic clusters extracted from binary solids. Besides providing a novel variable method for the introduction of alkenyl moieties to [Ge9] cluster compounds, this work expands the spectrum of mixed-functionalized [Ge9] cluster anions, which are suitable for the straightforward synthesis of zwitterionic compounds upon coordination to metal cations. In detail, the synthesis of a series of mixed-functionalized [Ge9] clusters is reported, including [Ge9{Si(TMS)3}3PRRI] (R=tBu, RI=(CH2)3CH=CH2; 2 ) and [Ge9{Si(TMS)3}2PRRI]− (R and RI: alkyl, alkenyl, aryl, aminoalkyl; 3 a to 11 a , TMS: (trimethyl)silyl). In 2 and 3 a , pentenyl functionalization of the [Ge9] clusters was achieved by reaction of the novel chlorophosphine tBu{(CH2)3CH=CH2}PCl ( 1 ) with silylated [Ge9] clusters. Furthermore, the reactivity of the cluster anions 3 a to 11 a towards NHCDippMCl (NHCDipp=1,3-di(2,6-diisopropylphenyl)imidazolylidine; M=Cu, Ag) showed a dependency on the steric demand of the phosphine either zwitterions ( 3 -MNHCDipp to 7 -MNHCDipp) featuring P–M interactions are formed, or Ge–M coordination ( 8 -MNHCDipp to 11 -MNHCDipp) occurs. For M=Ag, the formation of zwitterionic complexes was unequivocally proven by NMR investigations showing 1J(31P-107Ag/109Ag) spin-spin coupling. 相似文献
18.
Dr. Siew‐Peng Chia Dr. Emma Carter Dr. Hong‐Wei Xi Dr. Yongxin Li Dr. Cheuk‐Wai So 《Angewandte Chemie (International ed. in English)》2014,53(32):8455-8458
The two‐electron reduction of a Group 14‐element(I) complex [RË?] (E=Ge, R=supporting ligand) to form a novel low‐valent dianion radical with the composition [RË:]. 2? is reported. The reaction of [LGeCl] ( 1 , L=2,6‐(CH?NAr)2C6H3, Ar=2,6‐iPr2C6H3) with excess calcium in THF at room temperature afforded the germylidenediide dianion radical complex [LGe]. 2??Ca(THF)32+ ( 2 ). The reaction proceeds through the formation of the germanium(I) radical [LGe?], which then undergoes a two‐electron reduction with calcium to form 2 . EPR spectroscopy, X‐ray crystallography, and theoretical studies show that the germanium center in 2 has two lone pairs of electrons and the radical is delocalized over the germanium‐containing heterocycle. In contrast, the magnesium derivative of the germylidendiide dianion radical is unstable and undergoes dimerization with concurrent dearomatization to form the germylidenide anion complex [C6H3‐2‐{C(H)?NAr}Ge‐Mg‐6‐{C(H)‐NAr}]2 ( 3 ). 相似文献
19.
Gabriele Albertin Stefano Antoniutti Alessandra Botter Jesús Castro 《无机化学与普通化学杂志》2016,642(3):250-254
Ethylene complexes [OsH(η2‐CH2=CH2)L4]Y ( 1 , 2 ) [L = PPh(OEt)2, P(OEt)3; Y = OTf, BPh4] were prepared by reacting the dihydride OsH2L4 first with methyl triflate CH3OTf and then with ethylene (1 atm). Alternatively, the compound [OsH(η2‐CH2=CH2){PPh(OEt)2}4]OTf was prepared by allowing the dinitrogen derivative [OsH(N2){PPh(OEt)2}4]OTf to react with ethylene. Acrylonitrile CH2=C(H)CN reacts with OsH(OTf)L4 [L = P(OEt)3] to give the complex [OsH{κ1‐NCC(H)=CH2}{P(OEt)3}4]BPh4 ( 3 ). The complexes were characterized spectroscopically (IR and 1H, 13C, 31P NMR) and by X‐ray crystal structure determination of the [OsH(η2‐CH2=CH2){PPh(OEt)2}4]BPh4 derivative. 相似文献
20.
Vanadium(V) Oxo and Imido Calix[8]arene Complexes: Synthesis,Structural Studies,and Ethylene Homo/Copolymerisation Capability
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Prof. Dr. Carl Redshaw Dr. Mark J. Walton Dr. Darren S. Lee Chengying Jiang Dr. Mark R. J. Elsegood Dr. Kenji Michiue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):5199-5210
Interaction of p‐tert‐butylcalix[8]areneH8 (L8H8) with [NaVO(OtBu)4] (formed in situ from VOCl3) afforded the complex [Na(NCMe)5][(VO)2L8H]?4 MeCN ( 1 ?4 MeCN). Increasing [NaVO(OtBu)4] to 4 equiv led to [Na(NCMe)6]2[(Na(VO)4L8)(Na(NCMe))3]2?10 MeCN ( 2 ?10 MeCN). With adventitious oxygen, reaction of 4 equiv of [VO(OtBu)3] with L8H8 afforded the alkali‐metal‐free complex [(VO)4L8(μ3‐O)2] ( 3 ); solvates 3 ?3 MeCN and 3 ?3 CH2Cl2 were isolated. For the lithium analogue, the order of addition had to be reversed such that lithium tert‐butoxide was added to L8H8 and then treated with 2 equiv of VOCl3; crystallisation afforded [(VO2)2Li6[L8](thf)2(OtBu)2(Et2O)2]?Et2O ( 4 ?Et2O). Upon extraction into acetonitrile, [Li(NCMe)4][(VO)2L8H]?8 MeCN ( 5 ?8 MeCN) was formed. Use of the imido precursors [V(NtBu)(OtBu)3] and [V(Np‐tolyl)(OtBu)3] and L8H8, afforded [tBuNH3][{V(p‐tolylN)}2L8H]?3 1/2 MeCN ( 6 ?3 1/2 MeCN). The molecular structures of 1 to 6 are reported. Complexes 1 , 3 , and 4 were screened as precatalysts for the polymerisation of ethylene in the presence of cocatalysts at various temperatures and for the copolymerisation of ethylene with propylene. Activities as high as 136 000 g (mmol(V) h)?1 were sometimes achieved; higher molecular weight polymers could be obtained versus the benchmark [VO(OEt)Cl2]. For copolymerisation, incorporation of propylene was 7.1–10.9 mol % (compare 10 mol % for [VO(OEt)Cl2]), although catalytic activities were lower than [VO(OEt)Cl2]. 相似文献