Л THEORETICAL INVESTIGATION ON THE N—N BOND CLEAVAGE IN Ta(IV) HYDRAZIDIUM AND Ta(V) HYDRAZIDO COMPLEXES (300,00 руб.)

2016.  57,  1 UDC 541.49:546.9:541.6 A THEORETICAL INVESTIGATION ON THE N—N BOND CLEAVAGE IN Ta(IV) HYDRAZIDIUM AND Ta(V) HYDRAZIDO COMPLEXES N. Lu1, H. Wang2 2College of Forestry, Shandong Agricultural University, Taian City, Shandong Prov., P.R. China Received December, 15, 2014 1College of Chemistry and Material Science, Shandong Agricultural University, Taian City, Shandong Prov., P.R. China E-mail: lun@sdau.edu.cn Revised — February, 25, 2015 The reaction mechanism of the N—N bond cleavage in Ta(IV) hydrazido and hydrazidium complexes is studied using density functional theory. <...> The N—N bond cleavage in Ta(V) hydrazido gives terminal Ta(V) nitrido species. <...> In the tetrahydrofuran solvent, terminal Ta(V) nitrido dimerizes through a one-step direct pathway leading to the [Ta(V),Ta(V)] bis(€-nitrido) product. <...> Two Ta—N bonds form simultaneously between the Ta center of one molecule and the terminal N atom of another. <...> In the toluene solvent, there are two pathways of H atom abstraction and protonation producing mononuclear Ta(V) parent imide. <...> DOI: 10.15372/JSC20160106 Keywords: N—N bond cleavage, H atom abstraction, dimerization, protonation, density functional calculation. <...> Since the dissociation of the NN triple bond is extremely energy intensive, chemists have long searched for the development of efficient transition metal complexes [ 1 ] to mediate the low-energy process in a catalytic cycle such as the Schrock cycle [ 2, 3 ]. <...> The Mo(III) complexes were used by Schrock to realize the key N—N bond cleavage. <...> The charming Schrock cycle has initiated more and more efforts devoted to the development of other transition metals. <...> A breakthrough of group 4 metals was Shima™s dinitrogen cleavage by a trinuclear Ti polyhydride complex [ 5 ]. <...> Apart from the first complex with coordinated dinitrogen [Ru(NH3)5N2]2+, more achievements have been made about group 8 metals, especially in the aspects of Fe. <...> As a comparison, the studies of group 5 metal hydrazides remain relatively scarce. <...> Based on a large number of preliminary experimental works [ 12 ], Sita <...>