Date of Award
Doctor of Philosophy (PhD)
James D Hoefelmeyer
Transition metal (Hg, Ag, Pd, Ni, Sn, Cu) complexes and clusters form from the reaction of metal salts and QSnX (Q = quinolin-8-yl; X = Q or Cl) synthons. Our original intent was the use of Q2Hg, Q2Sn, or QSnCl as an ambiphilic ligand; however, we observed an apparent redox-trans metalation reaction in most of the cases. Bimetallic Hg-Ag complexes were prepared using Q2Hg as an ambiphilic ligand. Heterobimetallic (Ni-Sn and Pd-Sn) complexes were obtained from the reaction of NiCl2 (or PdCl2) with in situ generated QSnCl. Geometry and electronic configuration of the complexes were investigated using DFT methods. The NBO analysis predicts a two-fold interaction between Ni-Sn and Pd-Sn that includes an attractive covalent bonding component and a repulsive electrostatic component. Mayer Bond Order calculation suggests a low degree of covalent bonding between Ni-Sn and Pd-Sn bonds. This establishes that the QSn ligand may be acting as an ambiphilic ligand in the Ni-Sn and Pd-Sn complexes. Copper and palladium clusters were formed from redox transmetallation reactions using in situ generated Q2Sn, or Me2SnQ2 and Ph2SnQ2 ligands. An unusual structural motif, a low-valent, coordinatively unsaturated, M-m-Sn-M (M = Cu or Pd) atom was observed in clusters Q4Cu6Sn2, Q3Cu3Sn4, and Q4Cl2Pd4Sn2. X-ray studies prompted us to investigate their electronic structures using computational methods. QTAIM, MBO analysis, and CM5 charge models were calculated for the respective clusters. The atomic charge on this unusual tin atom was calculated in the range (-0.39) – (+0.08). This work demonstrates a new approach to synthesizing bimetallic clusters and molecules using QSnX.
Materials Science and Engineering
Cluster, DFT, NMR, Organometallics, XRD
Number of Pages
University of South Dakota
Bhowmick, Arjun Chandra, "(Quinolin-8-yl) Tin Synthons in Transmetalation Reactions with Transition Metals Yield Multimetallic Organometallic Molecules and Clusters" (2021). Dissertations and Theses. 74.
Available for download on Friday, September 13, 2024