Synthesis and structural characterization of monomeric mercury(ii) selenolate complexes derived from 2-phenylbenzamide ligands. Issue 9 (3rd February 2016)

• Record Type: Journal Article
• Authors: Patel, Saket; Meenakshi, ; Hodage, Ananda S.; Verma, Ajay; Agrawal, Shailendra; Yadav, Abhimanyu; Kumar, Sangit
• Is Part Of: Dalton transactions. Volume 45:Issue 9(2016)
• Page Start: 4030
• Page End: 4040
• Publication Date: 2016-02-03
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c5dt04356e
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The present work describes the synthesis and structural characterization of mercury selenolate complexes derived from 2-phenylbenzamide ligands and their isolation in monomeric form for the first time. Abstract : Monomeric Hg(ii ) selenolate complexes derived from 2-phenylbenzamide ligands were prepared by oxidative addition of diselenides [{C6 H4 (CONR2 )Se}2, R = Me, Et, i Pr] to elemental Hg and reductive cleavage of the Se–N bond of isoselenazolone derivatives [(NO2 )C6 H3 (CONSe)R, (R = allyl, n butyl)] followed by the treatment with HgCl2 . The complexes have been characterized by multinuclear NMR ( 1 H, 13 C and 77 Se) spectroscopy and mass spectrometry which suggest the monomeric form of these in solution. The molecular structures of diselenides [C6 H4 (CONR2 )Se]2 and mercury selenolates [Hg{(NO2 )C6 H3 (CONH-C3 H5 )Se}2 ], [Hg{C6 H4 (CON i Pr2 )Se}2 ] and [Hg{C6 H4 (CONMe2 )Se}2 ] were established by a single crystal X-ray diffraction study. Diselenides show strong intramolecular non-bonded Se⋯O interactions, which are influenced by the nature of C(O)NR̲2 and decrease with the sterically bulky alkyl substituent (Se⋯O = 2.823 Å for R = di-Me, 2.760 Å for R = allyl, and 3.157 Å for R = di- i Pr). Mercury complexes derived from less bulky 2-phenyl- N, N -dialkylbenzamide ligands associated with poor or no intramolecular non-bonded Hg⋯O interactions (4.91 Å for R = di-Me, 4.199 Å for R = allyl) and instead strong intermolecular Hg⋯O [2.792(3) and 2.820(4) Å] for di-Me and allyl and Hg⋯Se [3.3212(5) and 3.4076(8) Å] interactions were observed which lead to a dimeric form in the crystals. On the other hand, the mercury complex derived from the sterically bulky diisopropyl amide ligand shows a strong intramolecular non-bonded Hg⋯O (2.860 Å) interaction, adopts linear geometry and exists as a monomer. Thermogravimetric analysis (TGA) of the mercury selenolate complexes revealed two-step decomposition which leads to the formation of HgSe. The mercury selenolate complex3c derived from the sterically bulky 2-phenyl- N, N -diisopropylbenzamide ligand decomposed to give HgSe in the range of 220–300 °C.