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论文类型：期刊论文

发表时间：2017-12-25

发表刊物：ORGANOMETALLICS

收录刊物：SCIE、EI

卷号：36

期号：24

页面范围：4721-4726

ISSN号：0276-7333

摘要：The mechanisms of H-H and N-H bond cleavages of dihydrogen and ammonia mediated by the diiridium/i mu(2)-fmido complex [(Cp*Ir)(2)(mu(2)-H)(mu(2)-NH)](+)(A; Cp* =eta(5)-C5Me5) were theoretically investigated with the density functional theory (DFT) method. Both oxidative addition and metal-ligand cooperation modes have been studied for H-H and N-H bond cleavages, respectively. The H-H bond cleavage most likely occurs through competitive oxidative addition and metal-ligand cooperation, and both cleavage modes have similar overall free energy barriers (24.3 and 25.7 kcal/mol, respectively). The ligand-assisted N-H bond heterolytic cleavage mechanism is proposed for the NH(3)reaction, and the general oxidative addition pathway can be reasonably ruled out, as it is kinetically unfavorable.