Event Title

The Effect of Transition Metal Counter Ions on the Structure of Janus Head Ligands in Nickel-and Copper-Based Inorganic Compounds

Presenter Information

Hailing Cao

Faculty Advisor

William Dougherty

Start Date

24-4-2018 5:00 PM

End Date

24-4-2018 6:00 PM

Description

Reactions between copper(II) and bis-(2-pyridyl)phenylphosphine (PhPPy2) were examined to determine the effect of stoichiometry on the molecular structures of the products. PhPPy2 is classified as a Janus head ligand and features dual binding sites oriented in opposite directions which should result in structural diversity amongst the synthesized molecules. Varying the stoichiometry from 1:1 (PhPPy2:copper) to 1:2 and 2:1 resulted in the isolation of different colored products suggesting different copper coordination environment in each case. Changing the counter ion from chloride to nitrate also had an effect indicated by the green color of the chloride complexes and the blue color of the nitrate analogs. IR experiments show ligand-based vibrations, specifically C=C, C=N, and P-C bond stretches, consistent with the presence of the PhPPy2 ligand in all products. Due to the paramagnetic nature of Cu(II), crystallization trials were performed in order to identify the solid-state structures through X-ray crystallography; however, decomposition of the products during crystallization has hampered these studies.

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Apr 24th, 5:00 PM Apr 24th, 6:00 PM

The Effect of Transition Metal Counter Ions on the Structure of Janus Head Ligands in Nickel-and Copper-Based Inorganic Compounds

Reactions between copper(II) and bis-(2-pyridyl)phenylphosphine (PhPPy2) were examined to determine the effect of stoichiometry on the molecular structures of the products. PhPPy2 is classified as a Janus head ligand and features dual binding sites oriented in opposite directions which should result in structural diversity amongst the synthesized molecules. Varying the stoichiometry from 1:1 (PhPPy2:copper) to 1:2 and 2:1 resulted in the isolation of different colored products suggesting different copper coordination environment in each case. Changing the counter ion from chloride to nitrate also had an effect indicated by the green color of the chloride complexes and the blue color of the nitrate analogs. IR experiments show ligand-based vibrations, specifically C=C, C=N, and P-C bond stretches, consistent with the presence of the PhPPy2 ligand in all products. Due to the paramagnetic nature of Cu(II), crystallization trials were performed in order to identify the solid-state structures through X-ray crystallography; however, decomposition of the products during crystallization has hampered these studies.