Multinuclear magnetic resonance (/sup 31/P, /sup 77/Se, /sup 199/Hg) and electrochemical studies of nonlabile mercury(II) complexes with group 15/group 16 donor ligands

Journal Article · Wed May 18 04:00:00 EDT 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00283a008· OSTI ID:5833101

Bond, A M; Colton, R; Ebner, J

Multinuclear magnetic resonance (/sup 31/P, /sup 77/se, /sup 199/Hg) and electrochemical studies have been carried out on Hg(II) perchlorate complexes of pH/sub 2/PCH/sub 2/P(E)Ph/sub 2/ (E = S (dpmS), Se (dpmSe)) and Ph/sub 2/P(E)CH/sub 2/P(E)Ph/sub 2/ (E = S (dpmS/sub 2/), Se (dpmSe/sub 2/)) as well as the free ligands in dichloromethane, acetonitrile, and acetone with all results being independent of solvent. In all cases a single complex, (Hg(dpmE)/sub 2/)/sup 2+/ or (Hg(dpmE/sub 2/)/sub 2/)/sup 2+/, is formed, which is static at room temperature on the NMR time scale. Addition of excess ligand causes ligand exchange, but cooling slows the rate of ligand exchange, allowing observation of separate signals due to the mercury complex and free ligand. Coordination of selenium to mercury leads to a reduction of the phosphorus-selenium coupling constant relative to that in the free ligand, and mercury-selenium coupling is observed in some cases. Competitive exchange studies clearly show that mercury favors coordination to dpmE rather than dpmE/sub 2/. The electrochemical reduction of the complexes was studied at a mercury electrode. With the dpmE complexes, the processes are both chemically and electrochemically reversible, but in marked contrast, the dpmE/sub 2/ complexes exhibit chemical reversibility but electrochemical irreversibility, which is highly unusual for mercury complexes at a mercury electrode. This difference is explicable in terms of the preference of mercury for phosphorus rather than group 16 donor atoms. The reversible processes for the dpmE systems occur under conditions where both the mercury complex and the free ligand are present simultaneously at the electrode surface and mimic the NMR experiments where rapid exchange reactions occur. 32 refs., 5 figs., 4 tabs.

• Research Organization: Deakin Univ., Waurn Ponds (Australia)
• OSTI ID: 5833101
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:10; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
AROMATICS
CHEMISTRY
COMPLEXES
DATA
ELECTROCHEMISTRY
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
HEAVY NUCLEI
INFORMATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MERCURY 199
MERCURY COMPLEXES
MERCURY ISOTOPES
MINUTES LIVING RADIOISOTOPES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
RADIOISOTOPES
RESONANCE
SECONDS LIVING RADIOISOTOPES
SELENIUM 77
SELENIUM COMPOUNDS
SELENIUM ISOTOPES
STABLE ISOTOPES
SULFUR COMPOUNDS