Strongly blue-shifted C-H stretches: interaction of formaldehyde with hydrogen fluoride clusters.

摘要: The equilibrium structures, binding energies, and vibrational spectra of the cyclic, hydrogen-bonded complexes formed between formaldehyde, H2CO, hydrogen fluoride clusters, (HF)1≤n≤4, are investigated by means large-scale second-order Moller−Plesset calculations with extended basis sets. All studied exhibit marked blue shifts C−H stretching frequencies, exceeding 100 cm-1 for n = 2−4. It is shown that these are, however, only to a minor part caused blue-shifting bonding via C−H···F contacts. major arises due structural relaxation H2CO molecule under formation strong CO···H−F bond which strengthens as increases. close correlation different parameters in series demonstrated, consequences frequency pointed out, corroborating thus suggestion primary role f...