Experimental and computational investigations of platinum complexes of selenium diimide and some novel selenium–nitrogen ligands

Abstract

The reaction of selenium diimide Se[N(t-Bu)]2 and PtCl2 afforded an N,N′-chelated complex [PtCl2{N,N′-Se[N(t-Bu)]2}] (1) in good yield and [PtCl2{N,N′-SeO[NH(t-Bu)]2}] (2) as a minor product. Attempts to prepare 2 by direct reaction of SeOCl2 with Li[NH(t-Bu)] in toluene followed by addition of PtCl2 produced cyclic Se4[N(t-Bu)]4 in solution (77Se NMR spectrum) and a small amount of the complex [PtCl3{Se,Se′,Se″-Se4[N(t-Bu)]4}][Pt2Cl5{Se,Se′,Se″-Se3[N(t-Bu)]2}]·3MeCN (3·3MeCN), which contains tridentate Se4[N(t-Bu)]4 in the cation and the novel, acyclic bridging ligand [SeN(t-Bu)SeN(t-Bu)Se]2– in the anion. The reaction of Se[N(t-Bu)]2 with [PtCl2(NCPh)2] in THF produced the dinuclear complex [Pt2Cl6{SeN(t-Bu)C(Ph)NH}2]·2C4H8O (4·2THF) as the major product and only a few crystals of 1. The possible formation of SeO[NH(t-Bu)]2 or 2 by the reaction of Se[N(t-Bu)]2 or 1, respectively, with adventitious water and the pathway for the production of 4 were investigated through density functional theory calculations. The X-ray structures of 1, 2, 3·3MeCN, and 4·2THF have been determined.

Mercury- and Cadmium-Assisted [2 + 2] Cyclodimerization of tert-Butylselenium Diimide

“…1c For example, Se(N t Bu) 2 forms mononuclear N,N′-chelated complexes with SnCl 4 , 11e PdCl 2 , 11f and PtCl 2 . 12 In these complexes, the selenium diimide ligand is forced to adopt the energetically less favorable trans,trans configuration. The bridging N,N′coordination mode is found in the dinuclear coinage metal complexes [M 2 {μ-N,N′-Se(NR) 2 } 2 ] 2+ (M = Cu, Ag; R = t Bu, Ad) in which the ligands bridge an [M•••M] 2+ unit.…”