Crystal and molecular structures offac-[Re(Bid)(PPh3)(CO)3] [Bid is tropolone (TropH) and tribromotropolone (TropBr3H)]

Abstract

Two rhenium complexes, namely,fac-tricarbonyl(triphenylphosphane-κP)(tropolonato-κ2O,O′)rhenium(I), [Re(C7H5O2)(C18H15P)(CO)3] orfac-[Re(Trop)(PPh3)(CO)3] (1), andfac-tricarbonyl(3,5,7-tribromotropolonato-κ2O,O′)(triphenylphosphane-κP)rhenium(I), [Re(C7H2Br3O2)(C18H15P)(CO)3] orfac-[Re(TropBr3)(PPh3)(CO)3] (2) (TropH is tropolone and and TropBr3H is tribromotropolone), were synthesized and their crystal and molecular structures confirmed by single-crystal X-ray diffraction. Both crystallized in the space groupP-1 and display an array of inter- and intramolecular interactions which were confirmed by solid-state13C NMR spectroscopy using cross polarization magic angle spinning (CPMAS) techniques, as well as Hirshfeld surface analysis. The slightly longer Re—P distance of1[2.4987 (5)versus2.4799 (11) Å for1and2, respectively] suggests stronger back donation from the carbonyl groups in the former case, possibly due to the stronger electron-donating ability of the unsubstituted tropolonate ring system. However, this is not supported in the Re—CO bond distances of1and2.