Thirteen complexes of a type NiR(Y)Ln (R=CH3 (Me), C2H5 (Et); Y=OC6H5, p-cyanophenoxo, 8-phenylphenoxo, 8-quinolinolato, OCOEt, OCOPh, acetophenone oximato, acetylacetonato, benzoylacetonato, Cl; L=trie thy lphosphine (PEt3), 2,2′-bipyridine (bpy)) have been prepared by reactions of dialkylnickel(II) complexes NiR2L2 (1) with the corresponding active hydrogen compounds HY. Reactions of 1 with R′COY (Y=OC6H5, OCOC6H5, Cl) also afford the NiR(Y)Ln type complexes with formation of unsymmetrical ketones RCOR′. Reactions of 1 with alcohols lead to dehydrogenation of alcohols to afford aldehydes or ketones. The NiR(Y)Ln type complexes have been characterized by elemental analysis and spectroscopies (IR, NMR, visible). NMR spectra of trans-NiMe(OCOPh)(PEt3)2, NiMe(acetophenone oximato)(PEt3) (11), NiMe(benzoylacetonato) (PEt3) show temperature dependence, indicating occurrence of rapid dynamic reactions on NMR time scale in these complexes. The acetophenone oximato ligand in 11 is proposed to serve as an oxa-, aza-π-allylic ligand on the bases of IR and NMR spectroscopies. NiEt(OCOC2H5)(bpy) (8), NiEt(OCOC6H5)(bpy), and NiEt(Cl)(bpy) (14) undergo disproportionation reaction to give NiEt2(bpy) and NiY2(bpy) type complexes. Diethyl ketone is also produced during the disproportionation of 8. Reactions of 14 with olefins having electron-withdrawing substituents afford NiCl2(bpy) and Ni(olefin)2(bpy).
通过二烷基
镍(II)配合物NiR\(}_2\)L\(}_2\)(1)与相应的活泼氢化合物HY的反应,制备了13种NiR(Y)Ln类型的配合物(R = CH\(}_3\)(Me),C\(}_2\)H\(}_5\)(Et);Y = OC\(}_6}\)H\(}_5}\),对
氰基苯氧基,8-苯基苯氧基,8-
喹啉氧基,OCOEt,O
COPh,
苯乙酮肟基,
乙酰丙酮基,苯甲酰
丙酮基,Cl;L =
三乙基膦(PEt\(}_3}\)),2,2′-联
吡啶(bpy))。1与R′COY(Y = OC\(}_6}\)H\(}_5}\),OCOC\(}_6}\)H\(}_5}\),Cl)的反应也得到了NiR(Y)Ln类型的配合物,并形成了不对称的酮RCOR′。1与醇的反应导致醇的脱氢,得到了醛或酮。NiR(Y)Ln类型的配合物通过元素分析和光谱学(IR,NMR,可见光)进行了表征。trans-NiMe(O
COPh)(PEt\(}_3}\))\(}_2}\),NiMe(
苯乙酮肟基)(PEt\(}_3}\))(11),NiMe(苯甲酰
丙酮基)(PEt\(}_3}\))的NMR光谱显示了温度依赖性,表明在这些配合物中在NMR时间尺度上发生了快速动态反应。根据IR和NMR光谱学,11中的
苯乙酮肟基
配体被提议作为氧,氮-π-烯丙基
配体。NiEt(OCOC\(}_2}\)H\(}_5}\))(bpy)(8),NiEt(OCOC\(}_6}\)H\(}_5}\))(bpy),和NiEt(Cl)(bpy)(14)发生歧化反应,得到了NiEt\(}_2}\)(bpy)和NiY\(}_2}\)(bpy)类型的配合物。
二乙基酮也在8的歧化过程中产生。14与具有吸电子取代基的烯烃反应,得到了NiCl\(}_2}\)(bpy)和Ni(烯烃)\(}_2}\)(bpy)。