Kelling J. Donald

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Connections between the structures of Group 12 dihalides in their vapor and crystal phases are sought and discussed. The molecular structures of all monomers and dimers (MX(2): M=Zn, Cd, Hg and X=F, Cl, Br, I) were calculated at the density functional B3PW91 and MP2 computational levels. All the monomers are linear, with the mercury dihalide molecules(More)
Halogen bonding (R-X···Y) is a qualitative analogue of hydrogen bonding that may prove useful in the rational design of artificial proteins and nucleotides. We explore halogen-bonded DNA base pairs containing modified guanine, cytosine, adenine and thymine nucleosides. The structures and stabilities of the halogenated systems are compared to the normal(More)
The link between structural preferences in the monomers, dimers, and extended solid-state structures of the group 2 dihalides (MX(2): M = Be, Mg, Ca, Sr, Ba and X = F, Cl, Br, I) is examined theoretically. The question posed is how well are geometric properties of the gas-phase MX(2) monomers and lower order oligomers "remembered" in the corresponding MX(2)(More)
The most stable forms of E(5)Li(7)(+) (E = Ge, Sn, and Pb) have been explored by means of a stochastic search of their potential-energy surfaces by using the gradient embedded genetic algorithm (GEGA). The preferred isomer of the Ge(5)Li(7)(+) ion is a slightly distorted analogue of the D(5h) three-dimensional seven-pointed starlike structure adopted by the(More)
We find for distinct classes of halogen bonded complexes (MF3-X···Y) that the ab initio BSSE-corrected binding energies (ΔE) and enthalpies (ΔH) are predicted by functions of the form y = A/r(n) + C. Here X is a halogen atom, Y is a base, r is the X···Y separation, and A, n, and C are constants. The actual value of n (5.5 < n < 7.0 for ΔE) for each class is(More)
The existence and persistence of five-fold (quintuple) bonding in isomers of model RMMR molecules of quite different geometry are examined theoretically. The molecules studied are RMMR, with R = H, F, Cl, Br, CN, and CH3; M = Cr, Mo, and W. The potential energy surface of these molecules is quite complex, containing two, three, even four local minima. The(More)
Bonding interactions between an electron-deficient region (a sigma-hole) on M and electron donors in MF4-Base complexes, where M = C, Si, Ge, Sn, and Pb, are examined and rationalized. These interactions are seen to transition from weak primarily noncovalent interactions for all bases when M = C to stronger primarily covalent bonds in adducts as the valence(More)
A remarkable transition in the chemical bonding in (HgF2)n clusters as a function of n is identified and characterized. HgF2 is a fascinating material. Certain significant consequences of relativistic effects on the structure of the HgF2 molecule, dimer, and trimer disappear in the extended solid. Relativistic effects in Hg ensure that HgX2 molecules (X≡F,(More)
We examine the bonding possibilities of the bis(phenalenyl) MP(2) sandwich complexes of the divalent metals M = Be, Mg, Ca, Sr, Ba, Zn, Cd, and Hg, at the B3LYP level of theory. The outcome is an extraordinarily diverse class of low symmetry bis(phenalenyl)metal complexes in which bonding preferences and binding enthalpies differ dramatically. The lowest(More)