7T interactions

The structure is shown in Fig. 13.28a the interatomic angles and distances suggest that the bridging PhSb group is stabilized by Sb-Mn 7T interactions. A similar route leads to 3-coordinate planar organoarsinidine complexes which can also be prepared by the following reaction sequence ... 

Host-guest complex with 0---7T interaction only 186... 

Sugimoto T, Itagaki K, Irie K (2008) Design and physicochemical properties of new fluorescent ligands of protein kinase C isozymes focused on CH/7t interaction. Bioorg Med Chem 16 650-657... 

The structure of the 1 1 methanol solvate of olanzapine has been reported, where pairs of olanzapine molecules form a centrosymmetric dimer by means of C—H—-7t interactions [66]. The solvent molecule was linked to the drug substance through O—H-N, N—H O, and C—interactions. In a new polymorph of the 1 1 dioxane solvatomorph of (+)-pinoresinol, the structure was stabilized by O—H O hydrogen bonds between the compound and the solvent [67], Two new polymorphs of 2-cyano-3-[4-(/Y,jV-diethylamino)-phenyl]prop-2-enethioamide and its acetonitrile solvatomorph have been characterized [68], Although crystallization of the title compound was conducted out of a number of solvents, only the acetonitrile solvatomorph could be formed. 

Polyfunctional organomercurials have emerged as useful building blocks for the construction of supramolecular species. Compound 137, for instance, was shown to complex benzene, yielding extended binary stacks where the two components alternate (Figure 25).235 These stacks are rather compact (centroid distance of 3.24 A), so that secondary 7t-interactions occur between the benzene molecule and the mercury centers. Each of the six C-C bonds of the benzene molecule interacts with one of the six mercury centers of the two juxtaposed molecules of 137. As a result, the benzene is hexacoordinated in a fashion. The strength of the Hg-C interactions must... 

Ed71- is obtained by a DEL keylist (a standard option of the NBO program) that deletes the possible 7t—7t interaction elements from the density matrix and recalculates the SCF energy in the absence of such interactions. For all model DEL calculations described in this section we employed the simpler RHF/6-31 + G level of theory. 

Caldwell, J.W. and Kollman, P.A. (1995). Cation-7t interactions nonadditive effects are critical in their accurate representation. J. Am. Chem. Soc. 117, 4177-4178... 

The most intriguing substituent at the boron atom(s) of the nido-C4B2 framework is the amino group NR2 because of potential (N=B6)7t interactions which may weaken the B-B bonding in the cluster, because NPrl2 groups enforce a classical bicyclic structure 60 [79]. 

Nanocarbon electrodes can also be prepared by utilizing the n electrons of nanocarbons and glassy carbon (GC) electrodes. For example, Cai et al. simply dropped an aqueous solution of RGO onto a cleaned GC electrode and allowed the solvent to dry. The n-7T interactions were suitable for the subsequent deposition of Pt-Au nanostructures via electrochemical reduction of varying ratios of PtCl and AuC14 [133]. 

FIGURE 1.10 Comparison of enantiomer separations of DNB-Leu on quinine (QN) based and 0-9-(terf-butylcarbamoyl)quinine (tBuCQN) based CSPs. 1, ionic interaction 2, jt-7T-interaction 3, hydrogen bonding 4, steric interaction. Experimental conditions Eluent, methanol-0.1 M ammonium acetate (80 20 v/v) (pHa = 6.0) flowrate, 1 mLmin temperature, 25°C column dimension, 150 x 4 mm ID detection, UV 250 nm. Selector loadings, 0.37 and 0.30 mmol g l for QN- and tBuCQN-based CSPs, respectively. (Reproduced from A. Mandl et ah, J. Chromatogr. A, 858 1 (1999). With permission.)... 

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