N-[2-(4-Methoxyphenyltelluro)ethyl]benzamide (L1) and N-[2-(4-methoxyphenyl telluro)propyl] phthalimide (L2): synthesis and ligation with palladium(II), platinum(II) and ruthenium(II). Crystal structures of L1 and L2, the latter as a mixed crystal with L2H2

Abstract

The reactions of N-(2-chloroethyl)benzamide and N-[3-bromopropyl]phthalimide with ArTe− Na+ generated in situ by borohydride reduction of Ar2Te2, have resulted in N-[2-(4-methoxyphenyltelluro)ethyl]benzamide (L1) and N-[2-(4-methoxyphenyltelluro)propyl] phthalimide (L2) respectively. The L1 and L2 both exhibit characteristic 1H and 13C NMR spectra. The single crystal structures of L1 and L2, the latter as a mixed crystal with L2H2 are determined by X-ray diffraction (XRD). The Te---C(alkyl) bond length is 2.140(8)/2.149(4) Å and longer than Te---C(aryl), 2.107(8)/2.123(5) Å. The complexes having stoichiometries [PdCl2(L1)] (1), [PtCl2(L1)](2), [(Phen)Pd(L1)](ClO4)2 (3), [(DPPE)Pd(L1)](ClO4)2 (4) and [RuCl2(L2)2] (5) were synthesized and characterized by elemental analyses, conductance and molecular weight measurements, NMR (1H and 13C) and FT-IR spectra. The deshielding of CH2Te (0.2 ppm in 1H NMR and up to 22 ppm in 13C{1H} NMR) and NH signals (upto 0.8 ppm in 1H NMR) of 1–4, with respect to those of free L1 indicates that L1 coordinates with Pd–Pt(II) as a (Te, N) ligand. The CH2Te/CH2N signals in 1H and 13C NMR spectra of 5 appear deshielded (0.8/0.14 and 20/8 ppm, respectively), when compared with those of free L2, indicating ligation of L2 via Te and N.