Cadmium(II) complexes with phosphine tellurides: synthesis and multinuclear (³¹P, ¹²⁵Te, and ¹¹³Cd) NMR characterization in solution

Abstract

New cadmium(II) complexes with phosphine telluride ligands of the type CdX₂(R₃PTe)_n [X = ClO₄⁻, n = 4: R = n-Bu (1), Me₂ N (2), C₅H₁₀ N (3), C₄H₈ N (4) or OC₄H₈ N (5); X = Cl^–, n = 2: R = n-Bu (6), Me₂ N (7), C₅H₁₀ N (8), C₄H₈ N (9) or OC₄H₈ N (10)] have been synthesized and characterized by elemental analyses, IR and multinuclear (³¹P, ¹²⁵Te, and ¹¹³Cd) NMR spectroscopy. In particular, the solution structures of these complexes were confirmed by ¹¹³Cd NMR at low temperature, which displays a quintuplet for each of the perchlorate complexes and a triplet for each of the chloride complexes due to coupling with four and two equivalent phosphorus atoms, respectively, indicating a four-coordinate tetrahedral geometry for the metal center. These multiplet features were further accompanied by one bond Te–Cd couplings, clearly showing that the ligand is coordinated to the metal through tellurium. The results are discussed and compared with those obtained for closely related phosphine chalcogenide analogs.

Graphical Abstract

¹¹³Cd NMR spectrum of complex 2 in dichloromethane at 188 K (*: tellurium satellites).

Keywords:

• Phosphine telluride
• Cadmium complex
• ³¹P, ¹²⁵Te, and ¹¹³Cd NMR
• ¹J_Cd–Te coupling

Acknowledgments

We are grateful to the Tunisian Ministry of High Education and Scientific Research for financial support (LR99ES14) of this research.