RESUMEN
The interactions of FeBr2, CoBr2, NiBr2, and ZnBr2 with Ne, Ar, Kr, Xe, CH4, and N2 matrices have been investigated using IR, electronic absorption, and X-ray absorption spectroscopies as well as DFT calculations. ZnBr2 is linear in all of the matrices. NiBr2 is linear in all but N2 matrices, where it is severely bent. For FeBr2 and CoBr2 there is a more gradual change, with evidence of nonlinearity in Xe and CH4 matrices as well as N2. In the N2 matrices, the presence of νNN modes blue-shifted from the "free" N2 values indicates the presence of physisorbed species, and the magnitude of the blue shift correlates with the shift in the ν3 mode of the metal dibromide. In the case of NiCl2 and NiBr2, chemisorbed species are formed after photolysis, but only if deposition takes place below 10 K. There was no evidence for chemisorbed species for NiF2 and FeBr2, and in the case of CoBr2 the evidence was not strong.
RESUMEN
HgF(2) and Hg have been trapped in dilute F(2)/Ar and neat F(2) matrices, subjected to UV-Vis and vac-UV photolysis and annealing, with the products identified by FTIR, UV-Vis-NIR and Hg L(3)-edge XAFS spectroscopic techniques. Whilst there was no convincing evidence for the formation of HgF(4) under our argon matrix isolation conditions, a new Hg...F(2) complex was identified and subsequent photolysis yielded HgF(2) very cleanly. Hg L(3)-edge EXAFS has provided the first experimental value of 1.94(2) A for the Hg-F bond length in HgF(2), which is in excellent agreement with the computational values incorporating relativistic effects.