Studies On Synthesis And Reactivity Of Complexes Containing Multivalent Aluminum And Germanium

Organoaluminum chemistry has been a significant and exciting area of Main group chemistry,due to its widespread application in both fundamental and industrial fields.Organoaluminum complexes with the A1 center standing at low oxidation states,are considered as important intermediates in redox reactions.The synthesis of such species is still a challenge for experimental chemists.Organometallic alumoxanes and the chalcogen derivatives also play an important role in the aluminum chemistry.Germanium and aluminum fall in the diagonal position in the periodic table,and various research have been performed on germylenes.This dissertation focuses on the synthesis and reactivity of organometallic complexes containing multivalent aluminum and germanium,and six sections have been carried out and shown as follows:1.Synthesis and theoretical studies on neutral aluminum radical complex stabilized by cAACThe neutral radical(cAAC)2AlCl2(2)was synthesized by reduction of the cAAC-AlCl3(1)adduct with excess amount of KC8 in the presence of another equivalent of cAAC.The temperature range and excess amount of reduction reagent appeared to be crucial in this reaction.EPR measurement and theoretical calculations indicate that the delocalized unpaired electron is mainly located at the carbene carbon atoms,while a smaller contribution is from the aluminum center.This is the first example of a neutral radical with only one Al center.2.Synthesis and theoretical studies on asymmetric substituted Al-Al complexes via comproportionationThe reaction of LAl:(L = HC[C(Me)N(Ar)]2,Ar = 2,6-iPr2C6H3)with cAAC:?AlX3[X = Cl(1),I(4)]resulted in asymmetric Al(?)-Al(?)complexes LAl(X)-Al(X)2-cAAC[X = Cl(5);I(6)]via comproportionation.In these dialuminum(II)complexes the two A1 atoms bear different ligand environments,not only in respect of the different ligands but also according to the amount of coordinated halogen atoms.An applicable synthetic pathway for asymmetric Al(?)-Al(?)complexes was developed.3.Synthesis and characterization of soluble copper alumoxanesReactions of(CuMes)4 with aluminum monohydride LAl(R)OH(L =HC[C(Me)N(Ar)]2,Ar = 2,6-ir2C6H3,R = Me,Et)afforded the thermodynamically and kinetically stable Cu(I)alumoxane[LAl(R)OCu·MesCu]2[R = Me(8),Et(9)].Moreover,the reaction of the aluminum dihydroxide LAl(OH)2 with(CuMes)4 in a 2:1 ratio gave the same derivative[LAl(OH)OCu MesCu]2(10),and the reaction of(CuMes)4 andd LAl(OH)2 in a 1:1 ratio,which was carried out at 70 0C,resulted in the formation of the dimeric octanuclear Cu(I)complex[LAl(OCu·MesCu)2]2(11).These complexes demonstrate the potential assembling of Al-O-Cu prisms with sizable cavities.4.Synthesis and characterization of coinage aluminum sulfur speciesThe heterobimetallic cluster[LAl(SCu)2]2(12)and[LAl(SAg)2]4(13)was prepared for the first time by the reaction of aluminum-dithiol LAl(SH)2(L =HC[C(Me)N(Ar)]2,Ar = 2,6-iPr2C6H3)with(CuMes)4 and(AgMes)4,respectively.In addition,stable aluminum polysufides LAlS6(14)and LAIS4(15),as well as the heterocyclic complex LAl(?-S)2PNMe2(16),were also isolated from the system.Complexes 12 and 13 are the first examples of the coinage metals containing aluminum and sulfur.Meanwhile,for the first time the aluminum polysulfides species are obtained,which have only been studied by theoretical calculations before.5.Synthesis and characterization of cuprous and zincous aluminum selenidesThe aluminum-copper and aluminum-zinc selenides[LAl(SeCu)2]2(17)and[(LAlSe2)2Zn3Et2](18)were prepared by the reaction of LAl(SeH)2 with(MesCu)4 and ZnEt2,respectively.Complexes 17 and 18 contain the core structures of Al2Se4Cu4 and Al2Se4Zn3,respectively,which exhibit unique metal-organic frameworks.This paves a new pathway to the synthesis of aluminum-containing heterobimetallic selenides.6.Synthesis and nucleophilic coordination reaction of germanetelluronesA series of ?-diketiminato ligand stabilized germylenes L(R)Ge[R = Me(19),Cp(20),C=CFc(21)and C=CPh(22)]were prepared.Further reactions of the germylenes with Te powder leaded to germanetellurones L(R)Ge=Te[R = Me(23),Cp(24),C=CFc(25)and C=CPh(26)].The results indicate that the electronic effect of the substituted group binding to Ge center has significant influence on this reaction.Moreover,the reaction of 24 with GeC12·dioxane resulted in L(Cp)Ge=Te(GeCl2)(27),and reaction of L(Me)Ge=E(E =S,Se)with AuC6F5 formed L(Me)Ge=E(AuC6F5)(E=S(28),Se(29)),respectively.