Hexaisopropoxoniobates/tantalates of lathanides of the type [Ln{(μ‐OPri)2M(OPri)4}3] (M = Nb, Ln = Y( 1 ), La( 2 ), Nd( 3 ), Er( 4 ), Lu( 5 ); M = Ta, Ln = Y( 6 ), Gd( 7 )) have been prepared by the reactions of LnCl3.3PriOH with three equivalents of KM(OPri)6 in benzene. Reactions in 1:2 molar ratio of LnCl3.3PriOH with KTa(OPri)6 yielded derivatives of the type [{(PriO)3Ta(μ‐OPri)3}Ln{(μ‐OPri)2Ta(OPri)4}(Cl)] (Ln = Y( 8 ), Gd( 9 )), which on interactions with one equivalent of KOPri afforded [{(PriO)3Ta(μ‐OPri)3}Ln {(μ‐OPri)2Ta(OPri)4}(OPri)] (Ln = Y( 10 ), Gd( 11 )). All these derivatives have been characterized by elemental analyses and molecular weight measurements as well as by their spectroscopic [IR, 1H and 13C NMR (Y, La, Lu), electronic (Nd, Er)] studies. 89Y NMR studies have also been carried out on derivatives ( 6 ), ( 8 ), and ( 10 ). 相似文献
The reaction of 2‐methoxybenzyl alcohol with one molar equiv of R2AIX in diethyl ether at 0°C gives [(2‐MeOC6H4CH2‐μ‐O)AlRX]2 ( 1 : R = Et, X = Cl, 2 : R = X = Et). In addition, 2,4‐di‐tert‐butylphenol reacts with iBu3Al affording a four‐coordinated aluminum compound [(μ‐2,4‐tBu2‐C6H4O)Al(iBu)2]2 ( 4 ). Single crystal X‐ray structure analysis of 4 shows a C2h‐symmetry with a planar Al2O2 core. Ring‐opening polymerization (ROP) of caprolactones initiated by 1, 4 and [(μ‐OCH2C6H4OMe)Al(iBu)2]2 ( 3 ) is performed and polyesters with narrow molecular weight distributions were obtained from the “living” ROP of caprolactones. 1H NMR spectroscopic studies of PCL reveal that the initiator of 1 and 3 is through the Al‐OAr function, but the initiator of 4 is through the Al‐ iBu group. 相似文献
Polyethylenes and highly syndiotactic poly(propylene)s possessing chain end hydroxyl groups were synthesized by living polymerizations using L2TiCl2 [ 1 , L: C6F5NCH(2 O C6H3 3 tBu)]/MAO and functionalized α‐olefins, H2CCH(CH2)n Y [ 2 ; YOAlMe2, n = 4 ( 2a ); YOSiMe3, n = 9 ( 2b )]. Because the primary insertion of 2 to a cationic species L2Ti+ Me ( 3 ) derived from 1 /MAO is much faster than the successive secondary insertion of 2 , addition of an equimolar amount of 2 to 3 resulted in the quantitative formation of L2Ti+ CH2 CH(Me) (CH2)n Y [ 4 ; YOAlMe2, n = 4 ( 4a ); YOSiMe3, n = 9 ( 4b )]. These cationic species 4 served as functionalized initiators for the living polymerization of both ethylene and propylene and afforded polyolefins having extremely narrow molecular weight distributions and a hydroxyl group at the initiating chain end. The terminating chain end of the syndiotactic poly(propylene)s was also functionalized by adding an excess amount of 2b as a chain end capping agent to the living L2Ti–polymeryl species. Due to much slower insertion of the second molecule of 2b relative to the first one, the obtained polymers were end capped quantitatively by a single molecule of 2b . Telechelic syndiotactic poly(propylene)s were successfully synthesized through a living polymerization initiated by 4b and an end capping using 2b .
Reactions of bis ( g -diketonato) aluminium(III)-di- w -isopropoxo-di-isopropoxo-aluminium (III), [CH3COCHCOR)2Al( w -OPri)2Al(OPri) 2], with triphenylsilanol, Ph3SiOH, in 1:1 and 1:2 molar ratios and with diphenylsilanediol, Ph2Si(OH)2, in a 1:1 molar ratio, have resulted in the synthesis of [(CH3COCHCOR)2Al( w -OPri)2Al(OSiPh3)(OPri)], [(CH3COCHCOR)2Al( w -OPri)2Al(OSiPh3)2] and [(CH3COCHCOR)2Al( w -OPri)2Al(OSiPh2O], respectively. These are soluble in a variety of organic solvents ( e.g. , benzene, chloroform and dimethylsulfoxide) and show dinuclear behaviour in chloroform. These derivatives have been characterized by elemental analyses, molecular weight measurements, IR and NMR (1H, 13C and 27Al) studies. 相似文献
Synthesis and Characterization of New Intramolecularly Nitrogen‐stabilized Organoaluminium‐ and Organogallium Alkoxides The intramolecularly nitrogen stabilized organoaluminium alkoxides [Me2Al{μ‐O(CH2)3NMe2}]2 ( 1a ), Me2AlOC6H2(CH2NMe2)3‐2,4,6 ( 2a ), [(S)‐Me2Al{μ‐OCH2CH(i‐Pr)NH‐i‐Pr}]2 ( 3a ) and [(S)‐Me2Al{μ‐OCH2CH(i‐Pr)NHCH2Ph}]2 ( 4 ) are formed by reacting equimolar amounts of AlMe3 and Me2N(CH2)3OH, C6H2[(CH2NMe2)3‐2,4,6]OH, (S)‐i‐PrNHCH(i‐Pr)CH2OH, or (S)‐PhCH2NHCH(i‐Pr)CH2OH, respectively. An excess of AlMe3 reacts with Me2N(CH2)2OH, Me2N(CH2)3OH, C6H2[(CH2NMe2)3‐2,4,6]OH, and (S)‐i‐PrNHCH(i‐Pr)CH2OH producing the “pick‐a‐back” complexes [Me2AlO(CH2)2NMe2](AlMe3) ( 5 ), [Me2AlO(CH2)3NMe2](AlMe3) ( 1b ), [Me2AlOC6H2(CH2NMe2)3‐2,4,6](AlMe3)2 ( 2b ), and [(S)‐Me2AlOCH2CH(i‐Pr)NH‐i‐Pr](AlMe3) ( 3b ), respectively. The mixed alkyl‐ or alkenylchloroaluminium alkoxides [Me(Cl)Al{μ‐O(CH2)2NMe2}]2 ( 6 ) and [{CH2=C(CH3)}(Cl)Al{μ‐O(CH2)2NMe2}]2 ( 8 ) are to obtain from Me2AlCl and Me2N(CH2)2OH and from [Cl2Al{μ‐O(CH2)2NMe2}]2 ( 7 ) and CH2=C(CH3)MgBr, respectively. The analogous dimethylgallium alkoxides [Me2Ga{μ‐O(CH2)3NMe2}]2 ( 9 ), [(S)‐Me2Ga{μ‐OCH2CH(i‐Pr)NH‐i‐Pr}]n ( 10 ), [(S)‐Me2Ga{μ‐OCH2CH(i‐Pr)NHCH2Ph}]n ( 11 ), [(S)‐Me2Ga{μ‐OCH2CH(i‐Pr)N(Me)CH2Ph}]n ( 12 ) and [(S)‐Me2Ga{μ‐OCH2(C4H7NHCH2Ph)}]n ( 13 ) result from the equimolar reactions of GaMe3 with the corresponding alcohols. The new compounds were characterized by elemental analyses, 1H‐, 13C‐ and 27Al‐NMR spectroscopy, and mass spectrometry. Additionally, the structures of 1a , 1b , 2a , 2b , 3a , 5 , 6 and 8 were determined by single crystal X‐ray diffraction. 相似文献
Summary: The laser irradiation at 193 nm of a gaseous mixture of carbon disulfide and ethene induces the copolymerization of both compounds and affords the chemical vapour deposition of a C/S/H polymer, the composition of which indicates the reaction between two to three CS2 molecules and one C2H4 molecule. Polymer structure is interpreted on the basis of X‐ray photoelectron and FT‐IR spectra as consisting of >CS, >CC<, CH2 CH2 , (CC)SnC4 − n, C (CS) S , S (CS) S , and C S S C configurations. The gas‐phase copolymerization of carbon disulfide and ethene represents the first example of such a reaction between carbon disulfide and a common monomer.
Scheme showing the expected reaction of excited CS2 molecules with other CS2 molecules to form dimers, which then react with another CS2 molecule or add to ethene. 相似文献
Titanium(IV) complexes of the general formula TiL(OPri)2 [where LH2 = R CH3 where R = ─C6H5, ─C6H4Cl(p)] were prepared by the interaction of titanium isopropoxide with sterically hindered Schiff bases derived from heterocyclic β -diketones in 1:1 molar ratio in dry benzene. The complexes TiL(OPri)2 were used as versatile precursors for the synthesis of other titanium(IV) complexes. Titanium(IV) complexes of the type TiLL'(OPri) (where L'H═R1R2C═NOH, R1 = R2 = ─CH3; R1 = ─CH3,R2 = ─C6H5; R1 = ─COC6H5, R2 = ─C6H5) were synthesized by the reaction of TiL(OPri)2 with ketooximes (L'H) in equimolar ratio in dry benzene. Another type of titanium(IV) complexes having the general formula TiLGH(OPri) (where GH2═HO─G─OH, G = ─CH2─CH2─) have been prepared by the reaction of TiL(OPri)2 with glycol in 1:1 molar ratio in dry benzene. Plausible structures of these new titanium(IV) complexes have been proposed on the basis of analytical data, molecular weight measurements, and spectral studies. 相似文献
N-methyl-ethylidenimine (CH3 CHN CH3) was obtained by pyrolysis of 2-methylaziridine in a gas phase flow system, using quartz as a catalyst. Pyrolysis of aziridine gave mainly N-methyl-methylenimine (CH2N CH3). Under the conditions used in this work, pyrolysis of both compounds surprisingly showed cleavage of the CC-bond in the three-membered ring. No monomeric ethylidenimine (CH3 CHNH) could be isolated by pyrolysis of trimeric ethylidenimine (2,4,6-trimethyl-hexahydro-1,3,5-triazine), whereas N-vinyl-ethylidenimine (CH3 CHN CHCH2) could be identified as one of the pyrolysis products. NMR. data for N-methyl-ethylidenimine and N-vinyl-ethylidenimine are given for identification purposes. 相似文献
Reactions of Al(OPri)3 with LH2 =?[R′C(NYOH)CHC(R)OH] R=R′=CH3, Y =?(CH2)2 (L1H2); R =?CH3, R′ =?C6H5, Y =?(CH2)2 (L2H2); R =?R′ =?CH3, Y =?(CH2)3 (L3H2); R =?CH3, R′ =?C6H5, Y =?(CH2)3 (L4H2), in 1 : 2 molar ratio give mononuclear derivatives of aluminium AlLLH (1a–1d). Equimolar reactions of AlLLH with M(OPri)3 (M =?Al and B) yield homo- and hetero-dinuclear derivatives AlLLM(OPri)2 (M=Al=2a–2d M=B=3a–3d). Reaction of 2a with L1H2 affords AlL1L1AlL1 (4). All these derivatives have been characterized by elemental analysis, molecular weight measurements and plausible structures have been suggested on the basis of IR, NMR [1H, 13C, 27Al and 11B] spectral data and FAB-mass studies of 2b and 3b. Schiff base L1H2 and its mononuclear derivative with aluminium (AlL1L1H) have been screened for their antibacterial activity against Escherischia coli and Bacillus subtilis. 相似文献
Reactions of Zr{Al(OPri)4}2Cl2 or Zr{Nb(OPri)6}2Cl2 with KNb(OPri)6/KAl(OPri)4 and diethanolamines RN(CH2CH2OH)2 [R=H(LHH2), Me(LMeH2), and Ph(LPhH2)] in the presence of two equivalents of Et3N yield interesting hetero(bi- and tri-) nuclear derivatives (1)–(8) All of these new derivatives have been characterized by elemental analyses, molecular weight measurements, and spectroscopic studies.Ram C. Mehrotra - Deceased 相似文献
The μ‐amino–borane complexes [Rh2(LR)2(μ‐H)(μ‐H2B=NHR′)][BArF4] (LR=R2P(CH2)3PR2; R=Ph, iPr; R′=H, Me) form by addition of H3B?NMeR′H2 to [Rh(LR)(η6‐C6H5F)][BArF4]. DFT calculations demonstrate that the amino–borane interacts with the Rh centers through strong Rh‐H and Rh‐B interactions. Mechanistic investigations show that these dimers can form by a boronium‐mediated route, and are pre‐catalysts for amine‐borane dehydropolymerization, suggesting a possible role for bimetallic motifs in catalysis. 相似文献