Hydrogen-bonded intermolecular structure

Olanzapine appears to exist in at least five polymorphic forms, and the structure of Form II has been reported [32]. Two molecules form centrosymmetric dimmers stabilized by a series of C—H - rc interactions, and the dimmers are connected by a system of intermolecular N—C—and C—H S hydrogen bonds. The structure of a monoclinic polymorph of isoxsuprine hydrochloride has been reported [33], The molecular conformation existing in the new monoclinic polymorph was found to be very similar to that existing in the known triclinic polymorph. 

The doubly solvated 1 1 adduct of 24 and 2,2 -bipyridine, (C-methylcalix[4]-resorcinarene)(2,2 -bipyridine)(H20)(CH3OH) 32, also features a 2D hydrogen bonded network structure of C-methylcalix[4]resorcinarene and water [64]. There are four intermolecular hydrogen bonds arranged differently to those seen... 

The bent quasi-7i C—C bond of 1 is capable of forming different types of intra- and intermolecular bonding, e.g. it may serve as proton acceptor in hydrogen-bonded complexes. Structural characteristics of the complexes have been obtained from their MW spectra. 

Presence of native starch crystals. In plant materials, starch exists as semicrystalline, granular entities. Starch molecules, both amy-lose and amy lopectin, with their many intermo-lecular hydrogen bonds, give structure to the starch granule (Zobel, 1988). The crystalline regions formed by this intermolecular hydrogen bonding are somewhat resistant to enzyme hydrolysis and need to be broken prior to enzyme treatments. 

Figure 5.13 Hydrogen-bond interactions between raloxifene and ERa. Hydrogen-bond intermolecular interactions of 4-OH-tamoxifen cocomplexed with human ERa LBD using the X-ray crystallographic structure 1ERR at 2.6-A resolution [42] are shown. The conformation was visualized using 3D-Mol Viewer as in Figure 5.5.

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