A novel single‐electron sodium bond system of H 3 C···NaY (YH, OH, F, CCH, CN, and NC)

A novel single‐electron sodium bond system of H 3 C···NaH (I), H 3 C···NaOH(II), H 3 C···NaF(III), H 3 C···Na‐CCH(IV), H 3 C···NaCN (V) and H 3 C···NaNC (VI) complexes has been studied by using MP2/6‐311++G** and MP2/aug‐cc‐pVTZ methods for the first time. We demonstrated that the single‐electron sodium bond H 3 C···NaY formed between H 3 C and NaY (YH, OH, F, CCH, CN, and NC) could induce the NaY increased and stretching frequencies of I–IV and VI are red‐shifted, including the NaN bond in complex V is blue‐shifted abnormally. The interaction energies are calculated at two levels of theory [MP2, CCSD(T)] with different basis. The results shows that the strength of binding bond in group 2 (IV–VI) with π electrons are stronger than that of group 1 (I–III) without π electrons. For all complexes, the main orbital interactions between moieties H 3 C and NaY are LP 1 (C)→LP* 1 (Na). By comparisons with some related systems, it is concluded that the strength of single‐electron bond is increased in the order: hydrogen bond < bromine bond < sodium bond < lithium bond. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011