Journal of Inorganic and Organometallic Polymers and Materials

, Volume 20, Issue 3, pp 457–467

New Pt(II)(dithiolate) Compounds Possessing an Energetically Accessible Diphosphine-Based LUMO: Syntheses, Redox Properties, and Solid-State Structures of PtCl2(pbpcd), Pt(tdt)(pbpcd), and Pt(tdt)(bpcd)

  • Sean W. Hunt
  • Li Yang
  • Xiaoping Wang
  • Vladimir Nesterov
  • Michael G. Richmond
Article

DOI: 10.1007/s10904-010-9357-6

Cite this article as:
Hunt, S.W., Yang, L., Wang, X. et al. J Inorg Organomet Polym (2010) 20: 457. doi:10.1007/s10904-010-9357-6

Abstract

The new ligand 2-(pyren-1-ylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (pbpcd) has been synthesized from the Knoevenagel condensation using 1-pyrenecarboxaldehyde with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd). Displacement of the cod ligand in PtCl2(cod) by pbpcd furnishes PtCl2(pbpcd) (2) in near quantitative yield. Treatment of 2 with the dipotassium salt of toluene-3,4-dithiol (K2tdt) affords the dithiolate compound Pt(tdt)(pbpcd) (3) as a 1:1 mixture of diastereomers. An alternative synthesis of 3 from Pt(tdt)(bpcd) (5) and 1-pyrenecarboxaldehyde also affords 3 in 23% yield. The pbpcd ligand and all new diphosphine-substituted compounds have been isolated and fully characterized in solution by IR and NMR spectroscopies, and the solid-state structures of 2·CH2Cl2, 3·toluene, and 5·CH2Cl2 established by X-ray diffraction analyses. The solid-state structure of each product exhibits a square-planar architecture at the metal center. The redox properties of the pbpcd ligand and the tdt-substituted compound 3 have been explored by cyclic and differential-pulse voltammetry, and these data are discussed with respect to extended Hückel MO calculations and the nature of the HOMO and LUMO levels in each compound.

Graphical Abstract

The synthesis of the new ligand 2-(pyren-1-ylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (pbpcd) from the Knoevenagel condensation of 1-pyrenecarboxaldehyde with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) is reported. Reaction of pbpcd with PtCl2(cod) affords PtCl2(pbpcd), which in turn reacts with the dipotassium salt of toluene-3,4-dithiol (K2tdt) to yield Pt(tdt)(pbpcd). The latter complex may also be synthesized from the Knoevenagel condensation of Pt(tdt)(bpcd) with 1-pyrenecarboxaldehyde. The spectroscopic and electrochemical properties of the pbpcd ligand and Pt(tdt)(pbpcd) have been investigated, and the solid-state structures of three of the new Pt(II) compounds are reported.
https://static-content.springer.com/image/art%3A10.1007%2Fs10904-010-9357-6/MediaObjects/10904_2010_9357_Figa_HTML.gif

Keywords

Platinum compoundsDiphosphine ligandDithiolate ligandRedox chemistryMO calculationsX-ray crystallography

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Sean W. Hunt
    • 1
  • Li Yang
    • 1
  • Xiaoping Wang
    • 2
  • Vladimir Nesterov
    • 1
  • Michael G. Richmond
    • 1
  1. 1.Department of ChemistryUniversity of North TexasDentonUSA
  2. 2.Neutron Scattering Science DivisionOak Ridge National LaboratoryOak RidgeUSA