A three-step synthesis for the bifunctional ligand (phenyl)(pyridin-2- ylmethyl)phosphinodithioic acid, [2-C 5H 4N]CH 2P(S)(SH)(Ph) (3-H), was developed. The molecule was characterized by spectroscopic methods, and single crystal X-ray diffraction analysis, and the molecule found to exist in a zwitterionic form (3′). Protonation constants for 3′ were measured spectrophotometrically in 0.1 M NaClO 4 aqueous solution. The coordination chemistry of 3′ toward CdCl 2 and PtCl 2 was explored, and the complexes [Cd(3′)Cl 2] 2 and [Pt(3 -) 2]·CHCl 3 were isolated and structurally characterized by single crystal X-ray diffraction methods. Complexation constants for 3′ with Cd(II), Zn(II) and La(III), as a function of pH, were measured by titration techniques. An initial effort to prepare the [pyridin-bis(2,6-yl-methylphosphinodithioic acid)] analog of 3-H led to the formation and isolation of (phenyl)(6- methylpyridin-2-ylmethyl)phosphinodithioic acid, [2-C 5H 3N(6-CH 3)]CH 2P(S)(SH)(Ph) (6-H), that was characterized by spectroscopic methods and single crystal X-ray diffraction analysis. As found with 3-H, 6-H, adopts a zwitterionic structural form (6′).
Bibliographical noteFunding Information:
Financial support for this study was provided by the U.S. Department of Energy (DoE), Chemical Sciences, Geosciences and Biosciences Office, Office of Basic Energy Sciences (Grant DE-FG02-03ER15419 ) (RTP). In addition, funds from the National Science Foundation assisted the purchase of the X-ray diffractometer (CHE-0443580) and NMR spectrometers (CHE-0840523 and 0946690).
- Complexation constants
- Dithiophosphinic acid
- Protonation constants
- Pt(II) complexes
- X-ray crystal structures