. Author manuscript; available in PMC: 2012 Oct 30.

Published in final edited form as: Pure Appl Chem. 2012 Apr 29;84(9):1867–1875. doi: 10.1351/PAC-CON-11-10-21

Table 2.

The main structural parameters, the charge transfer between NH₄⁺ and C₂H_x, and binding energies of optimized NH₄⁺⋯C₂H_x (x = 2, 4, 6) complexes.^a

	NH₄⁺⋯C₂H₂	NH₄⁺⋯C₂H₄	NH₄⁺⋯C₂H₆
D_N-H (Å)	1.043	1.046	1.031
D_H-O (Å)	2.078	2.099	2.274 (2.142)
Δq (e)	0.043	0.055	0.015
E_b (kcal/mol)	−9.95	−9.99	−5.27

D_H-O is the distance between H of NH₄⁺ pointing to C₂H_x (x = 2, 4, 6) and the center of C-C, the data in parentheses denotes the distance between H of NH₄⁺ and its closer C atom. E_b was obtained at CCSD(T)/aug cc-pVTZ//MP2/aug-cc-pVTZ level of theory, including the MP2-estimated ZPE and BSSE corrections.