Synthesis and structural characterization of new organo-diimido and organo-imido niobium and titanium complexes
作者:Iván Dorado、Andrés Garcés、Carmen López-Mardomingo、Mariano Fajardo、Ana Rodríguez、Antonio Antiñolo、Antonio Otero
DOI:10.1039/b002743j
日期:——
The organo-diimido complexes [Nb(L2)Cl3}2(μ-1,4-NC6H4N)], L = CH3CN 1a or 4-tBupy 2a, [Nb(L2)Cl3}2(μ-1,3-NC6H4N)], L = CH3CN 1b or 4-tBupy 2b, and [Nb(L2)Cl3}2(μ-1,2-NC6H4N)], L = CH3CN 1c or 4-tBupy 2c were isolated by treating NbCl5 in the presence of CH3CN or 4-tBupy with the appropriate amount of the corresponding aniline N,N,N′,N′-tetrakis(trimethylsilyl)-1,4-, -1,3-, or -1,2-phenylenediamine, respectively. Compound 1a reacts with appropriate alkylating reagents to give the corresponding alkyl complexes, namely [NbLR3}2(μ-1,4-NC6H4N)], L = CH3CN, R = CH2SiMe33a; or CH2CMe33b; L = THF, R = CH2SiMe34a or CH2CMe34b. The crystal structure determination of 3a was carried out. Reaction of [Ti(py)3Cl2(NtBu)] with N,N,N′,N′-tetramethyl-1,4-phenylenediamine, in 2∶1 or 1∶1 stoichiometric ratio, afforded the organo-imido complexes [Ti(py)nCl2(1,4-NC6Me4NH2)], n = 3 (5a) or 2 (5b), while analogous reactions with 1,4- or 1,3-phenylenediamine give intractable mixtures of products. Organo-imido and organo-diimido titanium complexes were easily prepared by treating TiCl4 with the appropriate N,N,N′,N′-tetrakis(trimethylsilyl)phenylenediamines in CH2Cl2 in 1∶1 and 2∶1 molar ratios in the presence of 4-tert-butylpyridine or N,N,N′,N′-tetramethylethylenediamine (TMEDA). The compounds prepared in this way are [Ti(4-tBupy)2Cl21,4-NC6H4N(SiMe3)2}] 6a, [Ti(TMEDA)Cl21,4-NC6H4N(SiMe3)2}] 6b, [Ti(TMEDA)Cl21,3-NC6H4N(SiMe3)2}] 7b, [Ti(4-tBupy)2Cl2}2(μ-1,4-NC6H4N)] 8a, [Ti(TMEDA)Cl2}2(μ-1,4-NC6H4N)] 8b, [Ti(4-tBupy)2Cl2}2(μ-1,3-NC6H4N)] 9a and [Ti(TMEDA)Cl2}2(μ-1,3-NC6H4N)] 9b. Finally, the same reaction with N,N,N′,N′-tetrakis(trimethylsilyl)-1,2-phenylenediamine, in the presence of 4-tBupy or TMEDA, gives the diamido complexes [Ti(4-tBupy)2Cl21,2-C6H4(NH)2}] 10a and [Ti(TMEDA)Cl21,2-C6H4(NH)2}] 10b. The structures of the different families of complexes were determined by spectroscopic methods.
有机二亚胺络合物[Nb(L2)Cl3}2(μ-1,4-NC6H4N)],L = CH3CN 1a 或 4-tBupy 2a;[Nb(L2)Cl3}2(μ-1,3-NC6H4N)],L = CH3CN 1b 或 4-tBupy 2b;以及[Nb(L2)Cl3}2(μ-1,2-NC6H4N)],L = CH3CN 1c 或 4-tBupy 2c,通过将NbCl5与适量相应的苯胺N,N,N′,N′-四甲基硅基-1,4-、-1,3-或-1,2-苯二胺在CH3CN或4-tBupy存在下反应而得。化合物1a与适当的烷基化试剂反应,生成相应的烷基络合物,即[NbLR3}2(μ-1,4-NC6H4N)],L = CH3CN,R = CH2SiMe3 3a;或 CH2CMe3 3b;L = THF,R = CH2SiMe3 4a 或 CH2CMe3 4b。对化合物3a的晶体结构进行了测定。[Ti(py)3Cl2(NtBu)]与N,N,N′,N′-四甲基-1,4-苯二胺在2:1或1:1的化学计量比下反应,生成有机亚胺络合物[Ti(py)nCl2(1,4-NC6Me4NH2)],n = 3 (5a) 或 2 (5b),而与1,4-或1,3-苯二胺的类似反应则产生难以分离的混合物。有机亚胺和有机二亚胺钛络合物可以通过将TiCl4与适当的N,N,N′,N′-四甲基苯二胺在CH2Cl2中以1:1和2:1的摩尔比在4-叔丁基吡啶或N,N,N′,N′-四甲基乙烯二胺(TMEDA)的存在下反应而容易制备。以这种方式制备的化合物有[Ti(4-tBupy)2Cl21,4-NC6H4N(SiMe3)2}] 6a,[Ti(TMEDA)Cl21,4-NC6H4N(SiMe3)2}] 6b,[Ti(TMEDA)Cl21,3-NC6H4N(SiMe3)2}] 7b,[Ti(4-tBupy)2Cl2}2(μ-1,4-NC6H4N)] 8a,[Ti(TMEDA)Cl2}2(μ-1,4-NC6H4N)] 8b,[Ti(4-tBupy)2Cl2}2(μ-1,3-NC6H4N)] 9a 和 [Ti(TMEDA)Cl2}2(μ-1,3-NC6H4N)] 9b。最后,与N,N,N′,N′-四甲基-1,2-苯二胺在4-tBupy或TMEDA存在下进行的相同反应生成了二胺络合物[Ti(4-tBupy)2Cl21,2-C6H4(NH)2}] 10a 和 [Ti(TMEDA)Cl21,2-C6H4(NH)2}] 10b。不同类别络合物的结构通过光谱法进行确定。