Non-reactive interaction of ammonia and molecular chlorine: rotational spectrum of the ‘charge-transfer’ complex H₃N⋯Cl₂

Theoretical Insights into the Nature of Halogen Bonding in Prereactive Complexes

“…The effect on the N[001]H bond lengths is negligible. It is noted that the experimental value of Δ R (X-Y) for H 3 N⋅⋅⋅Cl 2 is +0.014 Å,[19] which is slightly shorter than the theoretical value in Table 3.…”

“…Comparison with the conventional CCSD(T)/aug-cc-pVTZ results of Karpfen indicates that the lower-level calculations produce intermolecular bond lengths that are too long by up to 0.06 Å,[37] and that MP2/aug-cc-pVTZ fortuitously produces geometries closer to CCSD(T)-F12b/VTZ-F12 than CCSD(T)/aug-cc-pVTZ does. The experimental estimates of the intermolecular bond lengths (2.708 Å for H 3 N⋅⋅⋅F 2 ,[17] 2.73 Å for H 3 N⋅⋅⋅Cl 2 ,[19] and 2.37 Å for H 3 N⋅⋅⋅ClF)[18] were obtained under the approximation that the monomer geometries do not change under complexation and are not directly comparable to the theoretical equilibrium geometry results in Figure 1, but it can be seen that the trends are much the same; the H 3 N⋅⋅⋅F 2 intermolecular distance is only slightly shorter than that in H 3 N⋅⋅⋅Cl 2 , with H 3 N⋅⋅⋅ClF shorter by approximately 0.36 Å.…”

Comparison between standard and counterpoise-corrected optimization using some hydrogen and halogen bonded systems

“…The B Á Á Á X bond lengths have previously been determined by experimental techniques for some dimers [20][21][22][23][24][25][26][27][28][29][30][31][32] Some optimized structures are minimum stationary points at the standard level whereas they are maximum stationary points at the CP-corrected level, and vice versa. For example, linear structures of N 2 Á Á Á HCl and N 2 Á Á Á HBr are ground states by the CP-corrected method and, with negative vibrational frequencies, are transition states by the standard method.…”

Präreaktive Komplexe der Dihalogene XY mit Lewis-Basen B in der Gasphase: eine systematische Studie der Halogen-Analoga B⋅⋅⋅XY der Wasserstoffbrückenbindungen B⋅⋅⋅HX

“…Die B-HX-Wechselwirkungen sind im allgemeinen vom schwachen elektrostatischen Typ, [67,68] und die k s -Werte lassen sich bei einer groûen Zahl von Komplexen über die empirische Gleichung (10) berechnen. [61,62] [32] (3.6) 5.1 [40] (6.3) 6.3 [45] (6.3) 7.0 [53] (6.9) C 2 H 2 ± (2.0) 5.6 [36] (5.4) ± (7.8) 9.4 [47] (9.5) 10.0 [54] (10.3) C 2 H 4 ± (2.2) 5.9 [27] (6.0) ± (8.7) 10.5 [46] (10.6) 11.0 [55] (11.5) HCN 2.6 [63] (2.3) 6.6 [37] (6.2) ± (9.1) 11.1 [49] (11.0) 12.3 [56] (12.0) H 2 S 2.4 [64] (2.6) 6.3 [35] (6.9) ± (10.0) 12.2 [48] (11.0) 13.3 [57] (13.2) NH 3 4.7 [65] (4.7) 12.7 [38] (12.6) 18.5 [39] ± (11.8) 5.9 (5.9) 5.2 [118] (4.9) H 2 S 12.0 (12.0) 6.8 (6.0) 5.9 (5.0) HCN 18.2 (18.2) 9.1 (9.1) 7.3 (7.7) NH 3 32.8 (30.0) [b] 17.6 (14.9) [76] 13.4 (12.5) [77] [a] Die experimentellen Werte sind aus Lit. [61] oder [62], falls nicht anders angegeben.…”