The cooperativity between hydrogen and halogen bonds

[[abstract]]The cooperativity between hydrogen bonds and halogen bonds in X-HCN-Y ( X: C2H2, H2O, NH3, HCl, HCN, HF; Y: HF, BrF, Br-2) is analyzed with MP2/6-311++G(d, p) and DFT/6-311++G(d,p) calculations using the B3LYP and mPW1PW91 hybrid functionals. The results from the quantum chemical calculations are typically clustered in groups according to the Y-ligand. By choosing the X-HCN-HF group as reference it is possible to describe the interaction between the hydrogen and the halogen bond with a two-parameter model. The value of the first parameter of the model describes the contribution of the X-ligand to the interbond cooperativity in the reference cluster. The second parameter of our model quantifies the changes in interbond cooperativity upon varying the Y-ligand. This simple model can be used to predict the cooperativity in X-HCN-Y trimers with reasonable accuracy and thereby to organize the results systematically. It is further shown that the conclusions drawn from this ordering scheme are independent from the computational method and thereby generally applicable.[[fileno]]2010305010053[[department]]化學