Abstract
Reaction of the quintuply-bonded dichromium Cr2[μ-η2-HC(N-2,6- iPr2C6H3)2]2 and BH3NH3 afforded Cr[η2-HC(N-2,6-iPr2C6H3)2(BH2NH2)] [η2-HC(N-2,6-iPr2C6H3)2(BH3)] (1). When more sterically hindered amine-boranes BH3NH2R (R = iPr, 2,6-iPr2C6H3) were used, a bis(σ-B-H) complex Cr[η2-HC(N-2,6-iPr2C6H3)2(BH3)]2 (2) was isolated. Moreover, reactions of the less sterically hindered quintuply-bonded dichromium Cr2[μ-η2-HC(N-2,6-Et2C6H3)2]2 with BH3NH3 and BH3NMe2H engendered the formation of a σ-borane complex Cr[η2-HC(N-2,6- Et2C6H3)2(BH3)]2 (3). Besides, reactions of Cr2[μ-η2-HC(N-2,6- iPr2C6H3)2]2 with nBu3SnH and H2 gave rise to the formation of a hydride- bridged complex, {Cr(μ-H)[μ-η2-HC(N-2,6-iPr2C6H3)2](THF)}2 (5), which gradually transformed to Cr2[μ-η2-HC(N-2,6-iPr2C6H3)2]2 through an unstable intermediate Cr2(μ-H)(THF)[μ-η2-HC(N-2,6-iPr2C6H3)2][μ-η2- HC(N-2,6-iPr2C6H3)(N-2-(η1-CH2)CH3CH-6-iPrC6H3)] (4). Exposure of a solution of Ru(Nacnac)Dipp(η6-p-cymene) (6a) ((Nacnac)Dipp = HC[C(Me)N-2,6-iPr2C6H3]2) to 1 equivalent of nitric oxide, three products were isolated: a dehydrogenatively dearomatized complex Ru(Nacnac)Dipp[η5-Me(C6H4)CMe2] (6h), a NO-bridged as well as thermally stable dinuclear complex [(μ-NO)Ru(Nacnac)Dipp]2 (7) with both ruthenium possessing 14-electron configuration, and a trinuclear complex Ru[(μ-NO)2Ru(Nacnac)Dipp]2 (8). When Ru(Nacnac)Dipp(η6- benzene) (10) was used to react with NO, 7 and Ru(Nacnac)Dipp{η5- [HC(C6H6)(C(Me)N-2,6-iPr2C6H3)2]}(11) were generated. KC8 reduction of Ru(Nacnac)Dipp(NO)2(OTf) (6c) also resulted in the isolation of complex 7. Moreover, exposure of solution 6a, 7, and 10 to excess nitric oxide, all led to the isolation of Ru(Nacnac)Dipp(NO)3 (6d) and (μ-κ1:κ1-O-N=N-O)[Ru(Nacnac)Dipp(NO)2]2 (6e). Reaction of 6e with a catalytic amount of 2,6-dimethylpyridine hydrochloride afforded 6d. 7 reacted with terminal alkynes RCCH (R = C3H7, Me3Si, Ph) to furnish the 3-legged piano-stool complexes [Ru(RCNN)](μ-NO)2[Ru(Nacnac)Dipp] (R = C3H7, 12a; Me3Si, 12b) and [Ru(PhCNN)](μ-NO)]2 (13) (CNN = HC(RCCH)[(2,6-iPr2C6H3)N=C(Me)]2). Addtionally, treatment of [(μ-Cl)Ru(η6-cymene)]2 with CH3COOK at 90 ℃ gave (μ-Cl)(μ-CH3COO)[Ru(η6-cymene)]2 (14). Reaction of Cr2[μ-η2-HC(N-2,6-iPr2C6H3)2]2 and excess nitric oxide produced an organic product HC(N-2,6-iPr2C6H3)[(NO)N-2,6-iPr2C6H3] (15).