Effect of fluorosubstitution in the ligand on structure, spectral and thermal characteristics of trimethylplatinum β-diketonate complexes

Abstract

This work is aimed at studying the structures, IR spectra and thermal properties of the series of trimethylplatinum complexes (Me3Pt(L)Py) with various combinations of β-diketonate (CβCOCγHCOCβ’) substituents: (1) Cβ,Cβ’=Me, acac - pentan-2,4-dionato; (2) Cβ=Me, Cβ’=CF3, tfac - 1,1,1-trifluoro-2,4-pentanedionato; (3) Cβ,Cβ’=CF3, hfac - 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato; (4) Cβ=tBu, Cβ’=CF3, ptac - 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione;(5) Cβ=Me, Cβ’=C2F5, 5Fac - 1,1,1,2,2-pentofluoro-3,5-hexandionato; (6) Cβ=Me, Cβ’=C3F7, 7Fac - 1,1,1,2,2,3,3-heptafluoro-4,6-heptandionato; Py - pyridine. The following crystallographic parameters, namely monoclinic P21/n, Z = 4, a = 11.8927(4) Å, b = 8.8446(4) Å, c = 16.9802(6) Å, β = 107.2490(10)°, V = 1705.75(11) Å3 and monoclinic P21/c, Z = 8, a = 9.7297(14) Å, b = 35.709(5) Å, c = 10.6785(11) Å, β = 91.035(2)°,V = 3709.5(8) Å3 have been determined for the crystals of 5 and 6, respectively. Hirshfeld surface analysis was used as a tool for visualization of intermolecular contacts and packaging features in the structures of Me3Pt(L)Py molecules depending on the combination of substituents in L. The effect of combination of β-diketonate substituents on the molecular structure and vibrational spectra of Me3Pt(L)Py derivatives was also studied. The density functional theory (DFT) calculations were used for the assignment of bands in their IR spectra. The thermal behavior of Me3Pt(L)Py complexes in the condensed phase were studied using TG, DSC methods. The complex 3 was tested as a precursor in MOCVD experiments.