| Organoaluminium hydrides are an important class of precursor in the synthesis ofmetal complexes, and they have a wide range of applications in coordination chemistry,biological chemistry, medical chemistry, material science, catalytic science, and many otherfields. This paper studied on the reactions of organoaluminium hydrides stablied by theβ-diketiminato ligand LAlH2(L=HC{C(Me)N(Ar)}2, Ar=2,6-iPr2C6H3) with organicboronic acid, organic phosphoric acid, alcohol, phenol, and amine, respectively. Andtwenty-five novel heteroaluminum hybrid system compounds were synthesized. In themeanwhile, the catalytic properties of three aluminum alkoxides were preliminarilyevaluated. Beside the two organoaluminum hydrides supported by o-(Me3SiN)2C6H4ligandwere also synthesized, and the product from ring-opening reaction of tetrahydrofuran wasdescribed. The new compounds in this dissertation were characterized by1H NMR,elementary analysis, and determined by single-crystal X-ray diffraction studies. The mainresults were summarized as follows:1. The reactions of LAlH2with organic boronic acid resulted in a series of novelcompounds bearing the Al–O–B moiety, and the reaction mechanism were also studied.LAl[OB(3-C4H3O)]2(μ-O)(1), LAl[OB(2-C4H4S)]2(μ-O)(2), LAl[OB(C5H9)]2(μ-O)(3),and LAl[OB(C5H9)]2(μ-O)(4) were synthesised by the reactions of LAlH2with aromaticheterocyclic boronic acids (furan-3-ylboronic acid, thiophen-2-ylboronic acid), aliphaticboric acids (cyclopentylboronic acid, butylboronic acid), respectively. Compounds1-4arerare examples containing a spiro-centered aluminum atom, where the inorganic AlO3B2ringis fused to the organic C3N2part. The result of the TGA and DSC of compound1showedthat it was stable below348oC. The reactions of four substituted phenylboronic acidsbearing different electronic effect (3-methylphenylboronic acid,3-fluorophenylboronic acid,4-chlorophenylboronic acid, and2-trifluoromethylphenylboronic acid) with LAlH2yieldeda series of boroxines-linked aluminum compounds LAl[OB(3-MeC6H4)]2(μ-O)(5)、LAl[OB(3-FC6H4)]2(μ-O)(6)、LAl[OB(4-ClC6H4)]2(μ-O)(7)、LAl[OB(2-CF3C6H4)]2(μ-O)(8), respectively. In contrast, two substituted phenylboronic acids(2,6-dimethylphenylboronic acid and2-biphenylboronic acid) with bulky steric effect wereemployed to synthesis two intermidates of boroxines-linked aluminum compoundsLAl[OB(2,6-CH3C6H4)OH]2(9) and LAl[(OB(2-PhC6H4)(OH)]2(10) with LAlH2. Compound9and10consists of the metallic-nonmetallic chain of(H)O–B–O–Al–O–B–O(H) as a backbone with two terminal B–OH groups. The reaction of3-hydroxyphenylboronic acid with LAlH2resulted in the first aluminium benzoboroxoleoxide LAl[(OB(o-CH2O)C6H4]2(11), which is formed from a compound with B–(OH)2andC-OH functionalities. However, the reaction of3-hydroxymethylphenylboronic acid withLAlH2gave the first eight-membered boroxine-linked dialuminum compound ofcomposition [LAlOB(3-OHCH2C6H4)]2(12) with a spiro center at each of the aluminumatoms. Furthermore, the reaction of LAlH2with2,6-dimethoxyphenylboronic acid resultedin an unexpected formation of (LAlO)2B(2,6-OCH3C6H4)(μ-O)(13). In the structure of13,two aluminum atoms, one boron atom, and three oxygen atoms form a six-membereddistorted Al2BO3ring. During the course of the reaction, the Al–H bond was hydrolyzedand the water resulted from the trimerization of2,6-dimethoxyphenylboronic acid.2. The reactions of LAlH2supported by bulky steric ligand with organic compoundswith P–OH, Si–OH, and–NH2functionalities were studied, respectively. Five novelaluminum compounds were synthesized and their molecular structures have beendetermined by X-ray single-crystal analysis. The reaction of phenylphosphonic acid withLAlH2, afforded a spirocyclic compound [LAl(μ-O)]2PO(Ph)(14). The central aluminumatom is located in the spirocyclic center where the inorganic AlPO2four-membered ring isfused to the organic C3N2part. In contrast, the reaction of diphenylphosphinic acid withLAlH2resulted in LAl[OPO(Ph)2]2(15), and it shows a P–O–Al–O–P framework.[LAl(μ-O)]2Si(Ph)2(16) was synthesized by he reaction of diphenylsilanediol with LAlH2.Compound16consists of the heterotrinuclear oxide with the metallic-non metallic chain of(H)Al–O–Si–O–Al(H) as a backbone. Furthermore, the reactions of LAlH2withbenzene-1,2-diamine, and2-aminophenol, yielded the aluminum imine heterocycliccompounds LAl(μ-NH)2(o-C6H4)(17) and LAl[(μ-N)(μ-S)](o-C6H4)(18), respectively.3. A series of novel aluminium alkoxides and aryloxides were synthesized from thereactions of LAlH2supported by bulky steric ligand with alcohols or phenolic compounds.The molecular structures of these compounds have been determined by X-ray single-crystalanalysis, and spectroscopic properties, respectively. Compound LAl(μ-O)2(o-C6H4)(19)contains the benzo-aluminum-dioxide organic-inorganic hybrid five-membered ring, whileLAl[(μ-O)(μ-OCH2)](o-C6H4)(20) shows the benzo-aluminoxane organic-inorganic hybridsix-membered ring. LAl(μ-O)2(p-Dithiane)(21) contains the organic-inorganic hybrid withthe AlO2C3S seven-membered rings, and forms a basket like molecule with the C4S2unit as the bottom part and the O2Al as the handle. However, compounds LAl(OC6H4NH2)2(22)、LAl(OCH2C6H4NH2)2(23)、LAl(9-OC13H9)2(24) and LAl(OC6H10NH2)2(25) exhibit theC–O–Al–O–C chain structure. Furthermore, Compounds23,24, and25show excellentactivities for ROP of-caprolactone. It was observed that the catalytic activity of the threecompounds varied depending on the substituent group at the aluminum center. The activitywas indicated in the order as23>25>24.4. The synthesis and characterization of the two organoaluminium hydrides with1,6-bis-(trimethylsilylamino)benzene (o-(Me3SiN)2C6H4) ligand were described. Thereaction of1,6-bis-(trimethylsilyamino)benzene in toluene with H3Al·NMe3in a molarratio of1:1, resulted in the formation of [1,6-(Me3SiN)2C6H4]AlH(NMe3)(26), while thereaction of1,6-bis-(trimethylsilyamino)benzene with H3Al·NMe3in tetrahydrofuran led toan unprecedented formation of {[1,6-(Me3SiN)2C6H4]Al}2O(CH2)4NMe3(27). Compound26is the first monomeric aluminum hydride compound containing the1,6-bis-(trimethylsilylamino)benzene. Compound27exhibits an intramolecular zwitterionof composition–O(CH2)4NMe3+between two aluminum atoms. We reasoned that theformation of27may involve26as the intermediate compound. |
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