Variation of M···H–C Interactions in Square-Planar Complexes of Nickel(II), Palladium(II), and Platinum(II) Probed by Luminescence Spectroscopy and X-ray Diffraction at Variable Pressure

Abstract

Luminescence spectra of isoelectronic square-planar d complexes with 3d, 4d, and 5d metal centers show d-d luminescence with an energetic order different from that of the spectrochemical series, indicating that additional structural effects, such as different ligand-metal-ligand angles, are important factors. Variable-pressure luminescence spectra of square-planar nickel(II), palladium(II), and platinum(II) complexes with dimethyldithiocarbamate ({CH}DTC) ligands and their deuterated analogues show unexpected variations of the shifts of their maxima. High-resolution crystal structures and crystal structures at variable pressure for [Pt{(CH)DTC}] indicate that intermolecular M···H-C interactions are at the origin of these different shifts.

DFT Investigation of the Molecular Properties of the Dimethylglyoximato Complexes [M(Hdmg)2] (M = Ni, Pd, Pt)

“…The O-H symmetric and asymmetric stretching modes in the calculated IR spectra of [Ni(Hdmg) 2 ] are far lower (2174 and 2240 cm -1 ) than those of [Pd(Hdmg) 2 ] (2939 and 2964 cm -1 ) and [Pt(Hdmg) 2 ] (2857 and 2934 cm -1 ) (Figure 2, Tables 1-3). The calculated values are perfectly in keeping with our calculated structural data and in line with increasing ionic radii for the metals (Pd 2+ > Pt 2+ >> Ni 2+ ) [63][64][65]67] weakening the H bond. For the asymmetric O-H .…”

“…The calculated HOMO-LUMO energy gaps are 6.302 and 6.413 eV for the Ni and Pd complexes, respectively and reduced to 6.062 eV for the Pt complex, which is caused by a marked stabilisation of the LUMO (Figure 3). This series Pd > Ni > Pt agrees quite well with the experimental binding energies and electrochemical or optical HOMO-LUMO gaps of comparable series of Pt, Pd, and Ni complexes [63][64][65]67,77].…”

“…Recently reported DFT and TD-DFT calculations on the molecular and electronic structures of planar d 8 configured Ni II , Pd II , and Pt II complexes have shown that the reliability of calculated data with experimental data [58][59][60][61][62][63][64][65][66] is very much dependent on functionals and basis sets. Furthermore, comparative DFT and experimental studies for these three metals were recently reported [62][63][64][65][66][67] allowing to gauge for the differences of these three metals.…”

Post-Synthetic Functionalization of Ni-MOF by Eu3+ Ions: Luminescent Probe for Aspartic Acid and Magnetic Property

“…H 4 odip and 1 had emission peaks at 405 and 470 nm under excitation of 349 and 320 nm, respectively (Figure S8). But, the luminescence of 1 is very weak, and such low-energy emission could be ascribed to the fact of existing unpaired electrons in Ni 2+ ions, as well as that the visible torsion in 1 , increases the deformation of the ligand and reduces the conjugation. , The weak luminescence was further reflected by the invisible emission color of 1 under UV-light irradiation (Figure ). When excited at 332 nm, Eu 3+ @ 1 showed five emission bands at 578, 593, 615, 650, and 693 nm, which can be assigned to Eu 3+ ions characteristic transitions of 5 D 0 → 7 F J ( J = 0, 1, 2, 3, 4) (Figure ).…”

Structural study of Pt(II) and Pd(II) complexes with quinoline-2-carboxaldehyde thiosemicarbazone

“…One line of our previous research has been focused on synthesis, characterization and biological activity evaluation of d-metal complexes with α-N-heterocyclic chalcogensemicarbazones, predominantly derivatives of 2-formylpyridine and quinoline-2-carboxaldehyde. [7][8][9][10][11][12][13][14] Taking into account that many properties of chemical systems are defined not only by the molecular structure but also by weak intermolecular interactions, 15,16 herein the synthesis and characterization of Pd(II) and Pt(II) complexes with quinoline-2-carboxaldehyde thiosemicarbazone, with the main focus on solid state structures and main interactions that govern the crystal packings, are reported. Both chosen ions have a d 8 electronic configuration and almost the same ionic radii; thus, their complexes with the same ligand systems are often isostructural.…”