Reaction Studies of the Mo-Mo Quintuple Bond with Aza-Containing Arenes, Nitriles and White Phosphorus

• Main Authors: Feng, Ya-Hsuan, 馮雅瑄
• Other Authors: Tsai, Yi-Chou
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/apazj2

碩士 === 國立清華大學 === 化學系所 === 106 === This thesis reports reactions of the amidinate-supported quintuply bonded dimolybdenum complex, Mo2[μ-2-HC(N-2,6-iPr2C6H3)2]2 (1), with various aza-containing arenes, nitriles, and P4. Two different products was obtained from the reaction of 1 and 2,2'-bipyridine, Mo2(μ-η2-1,2:η2-4,5-C10H8N2)[μ-κ2-HC(N-2,6-iPr2C6H3)2]2 (2) and (η2-C10H8N2)2Mo2[μ-κ2-HC(N-2,6-iPr2C6H3)2]2 (3). In complex 3, 2,2'-bipyridine coordinated to Mo centers via its lone pairs of nitrogen atoms, which is the usual coordination mode of the aza-containing arenes. By contrast, 2,2'-bipyridine of 2 coordinates to Mo centers through an η4-bonding mode. Treatment of 1 with isoquinoline, quinoxaline, or quinoline generated the quadruply bonded dimolybdenum compounds, Mo2(μ-η2-1,2:κ1-4-R)[μ-κ2-HC(N-2,6-iPr2C6H3)2]2 (R = C9H7N (4), C8H6N2(5)), and Mo2(H)(μ-κ2-C9H7N)[μ-κ2-HC(N-2, 6-iPr2C6H3)2]2 (6), respectively. It is interesting to note that both complexes 4 and 5 contain η3-bound arene ligands, while C-H bond activation was oberved in complex 6. The reactions of 1 with methy-l-4-cyanobenzoate, 4-methoxybenzonitrile, or 1,8-naphthalenedicarbonitrile led to the isolation of [2+2+2] cycloaddition products: Mo2[μ-κ2-NC(R)C(R)N][μ-κ2-HC(N-2,6-iPr2C6H3)2]2 (R = C6H4CO2CH3 (7), C6H4OCH3 (8), C5H3 (9)), respectively. On the other hand, 1 reacted with 4-(dimethylamino)benzonitrile to yield C-H bond activation product [κ1-NCC6H4N(CH3)2][μ-κ1-NC(H)C6H4NH(CH3)2]Mo2[μ-κ2-HC(N-2,6-iPr2C6H3) (N-2-iPr-6-CH(κ1-CH2)CH3-C6H3][μ-κ2-HC(N-2,6-iPr2C6H3)2] (10). It is noteworthy that we isolated interesting compounds (C16H8)(μ-κ2-N2)2{Mo2[μ-κ2-HC(N-2,6-iPr2C6H3)2]2}2 (11) and [μ-κ1-N:μ-κ2-N-(C6H5CN)2]2Mo2[μ-κ2-HC(N-2,6-iPr2C6H3)2]2 (12) from the reactions of 1 with 1,2-benzenedicarbonitrile, or [1,1'-biphenyl]-2,2'-dicarbonitrile, respectively. Moreover, we successfully synthesized a novel cyclic-P5 bound dimolybdenum dimer, (μ-η2:η2-P5)2[Mo2{μ-κ2-N-HC(2,6-iPr2C6H3)2}2]2 (15). Further reduction of complex 15 by KC8 led to the formation of the first cyclo-P5 anion coordinated dimolybdenum complex, (μ-[K222-cryptand][Mo2(μ-η2:η2-P5){μ-κ2-N-HC(2,6-iPr2C6H3)2}2].