Reactivity Study of Low-valent Vanadium and Ruthenium β-Diketiminates

• Main Authors: Hsieh, Chang-Cheng, 謝昌呈
• Other Authors: Tsai, Yi-Chou
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/23537058239182854833

碩士 === 國立清華大學 === 化學系 === 101 === In order to activate dinitrogen, reduction of the trivalent vanadium β-diketiminate (Nacnac)DippVCl2 ((Nacnac)Dipp = HC(C(Me)N-2,6- iPr2C6H3)2) by KC8 in the presence of a σ-donor, such as pyridine or 4-dimethylaminopyridine (DMAP), under dinitrogen atmosphere led to the isolation of [V(NC5H5)(μ-Cl)(Nacnac)Dipp]2 (1) with two chloro ligands bridging two vanadium atoms. Meanwhile, the imido complex [(2,6-iPr2C6H3)NC(CH3)CHC(CH3)VN(2,6-iPr2C6H3)(N2C7H10)] (2) formed via a β-diketiminato ligand degradation was also isolated. Reactions of the univalent vanadium inverted-sandwich complex (μ-η6:η6-C7H8)[V(Nacnac)Dipp]2 (3) with diaza-containing arenes have also been investigated. Seven- and eight-membered diaza metallacycles V(Nacnac)Dipp[NC4H4N] (4), V(Nacnac)Dipp(NC8H6N) (5) and [(μ-NC(Ph)N)V(Nacnac)Dipp]2 (7) were obtained via ring opening of pyridazine, phthalazine and 3,6-diphenyl-1,2,4,5-tetrazine. However, benzo[c]cinnoline acts as a σ-donor when reacted with 3 to give (η2-benzo[c]cinnoline)2V(Nacnac) Dipp (6). Nitric oxide activation by Ru β-diketiminate was also investigated. Reactions of the univalent half-sandwich ruthenium complex [Ru(nacnac)Dmp(η6-p-cymene)] with an excess amount of NO at 0°C, yielded a dinuclear ruthenium complex (μ-κ1: κ1-O-N=N-O)[Ru(nacnac)Dmp(NO)2]2 (9), where two Ru centers is linked together by a hyponitrito ligand resulted from the coupling of two two NO. On the other hand, exposure of 8 to an excess amount of NO at room temperature yielded the complex (μ-κ2: κ2-NO)(μ-NO)[Ru(nacnac)Dmp(NO)]2 (10), in which two Ru atoms are bridged by one NO ligand in a remarkable side-on fashion. Interestingly, introduction of an excess amount of NO into the Ru(II) β-diketiminate [Ru(nacnac)Dmp(η6-p-cymene)](OTf) (11) and [Ru(nacnac)Dmp(Cl)(η6-p-cymene)] (12) resulted in the formation of Ru(nacnac)Dmp(NO)2 (OTf) (12) and Ru(nacnac)Dmp(NO)Cl2 (13). Reduction of both 12 and 13 with KC8 gave complex 10.