Inter- versus Intramolecular Structural Manipulation of a Dichromium(II) Pacman Complex through Pressure Variation

The
effect of pressure on the intranuclear M···M
separation and intermolecular secondary interactions in the dinuclear
chromium Pacman complex [Cr2(L)]­(C6H6) was evaluated because this compound contains both a short Cr···Cr
separation and an exogenously bound molecule of benzene in the solid
state. The electronic structure of [Cr2(L)] was determined
by electron paramagnetic resonance spectroscopy, SQUID magnetometry,
and density functional theory calculations and shows a diamagnetic
ground state through antiferromagnetic exchange, with no evidence
for a Cr–Cr bond. Analysis of the solid-state structures of
[Cr2(L)]­(C6H6) at pressures varying
from ambient to 3.0 GPa shows little deformation in the Cr···Cr
separation, i.e., no Cr–Cr bond formation, but instead a significantly
increased interaction between the exogenous arene and the chromium
iminopyrrolide environment. It is therefore apparent from this analysis
that [Cr2(L)] would be best exploited as a rigid chemical
synthon, with pressure regulation being used to mediate the approach
and secondary interactions of possible substrates.