Abstract
Abstract In the presence of benzo-15-crown-5 ether, KC8 reduction of Mo2Cl2[μ-HC(N-p-tolyl)2]3 resulted in the isolation of a quadruply-bonded paddlewheel complex, Mo2(µ-HC(N-p-tolyl)2)3C12- µ-K(benzo-15-crown-5) (1). When the amount of KC8 was increased from 2 to 6 equiv, a dimeric tetranuclear complex [Mo2(µ-HC(N-p-tolyl)2)3(µ-o-OC6H4O(CH2CH2O)3□K)]2 (2) was generated by a 2-electron reductive cleavage of two C-O bonds of the benzo-15-crown-5 ether. Reaction of a mixture of CoI2 and lithium pentamethylcyclopentadienide with polyolefins, 1,5-cyclooctadiene and 1,3,5,7-cyclooctatetraene, led to the formation of three known complexes (η5-C5Me5)Co(η4-C8H12), [(η5-C5Me5)Co]2(µ-η4:η4-C8H8) and (η5-C5Me5)Co(η4-C8H8) (3), respectively. However, treatment of a mixture of NiI2 and lithium pentamethylcyclopentadienide with polyolefins gave rise to a series of C-C coupling complexes (η5-C5Me5)Ni(η1:η2-2-η1-C5Me5-cyclooct-5-enyl) (4), (η5-C5Me5)Ni (η1:η2-2-η1-C5Me5-cyclooct-3,5-diene-7-enyl) (6) and (η5-C5Me5)Ni (η1:η2-3-η1-C5Me5-cyclooct-2,5-diene-7-enyl) (7), which were formed via a C-C coupling between the pentamethylcyclopentadienide and the polyolefin. Interestingly, when the amount of lithium pentamethylcyclopentadienide was reduced, two inverted-sandwich dinickel complexes [(η5-C5Me5)Ni(η4-C8H12)][(µ-η5:η5-C5Me5)(NiI2)2] (5) and [Li(THF)4][(µ-η5:η5-C5Me5)(NiI2)2] (8) were obtained. Besides, reduction of (η5-C5Me5)RuCl(η4-C8H12) by KC8 led to the isolation of a hydride complex, (η5-C5Me5)RuH(η4-C8H10) (9). Treatment of the inverted-sandwich divanadium complex (µ-η6:η6-C7H8)[V(Nacnac)]2 (Nacnac = HC(C(Me)NC6H3-2,6-iPr2)2) with CO engendered the formation of [(Nacnac)V](µ-η1:η1-CO)3 [V(Nacnac)(THF)] (10), where three isocarbonyl ligands bridge two vanadium centers in an “end-on” mode. Notably, complex 10 can also be generated from the injection of CO to the vanadium bis(imido) complex (Nacnac)V(NSiMe3)2, whereas (Nacnac)V(NSiMe3)2 can not be obtained from reaction of Me3SiN3 and complex 10.