Hydrothermal crystallization of organic compounds

The background of our studies in hydrothermal crystallization of organic compounds and in particular the ideas of organic crystal-engineering based on supramolecular principles is presented in Chapter 1.; Chapter 2--5 then describe the application of hydrothermal conditions to the preparation of organic co-crystals of aromatic acids and bases. In general when comparing hydrothermal and ambient crystallization for these systems, hydrothermal conditions appear advantageous in producing higher yield, higher phase purity products, readily isolated and frequently with enhanced crystal size up to several mm in dimension.; This topic is commenced in Chapter 2, which describes the synthesis and structures of eleven new co-crystals of bipyridines with isopththalic and terephthalic acids. Through appropriate variations of conditions co-crystal of 1:1 or 1:2 stoichiometry can be formed for the isophthalic system. In the 1:1 adducts linear zig-zag chains are found though they can occur with different polymorphic forms, as found for each of the 1:1 co-crystals [Bipy][IPA-H 2] and [BPEA][IPA-H2]. The 1:2 stoichiometry compounds involve association of the isophthalic acids with the pyridines through O-H...N hydrogen bonds and themselves through O-H...O H-bonding.; Chapter 3 describes the related chemistry of the co-crystals formed between bipyridines (bipy), (BPEA) and (BPEE) and phthalic acid (PHA-H2). Once again crystal of 1:1 and 1:2 stoichiometry may be formed. The 1:1 compounds are neutral molecular adducts with O-H...N hydrogen bonding, and several polymorphic forms are found, for bipy, BPEA and BPEE. The 1:2 compounds are different in having proton transfer have bipyridinium dications and the hydrogen-phthalate mono-anions [Bipy-H2][PHA-H]2.; Chapter 4 describes the co-crystals of various bipyridines with hemi-mellitic acid [HEM-H3]. Again different stoichiometries co-crystals are found along with polymorphs. The hem-mellitates have strong tendency to segregate hydrophilic and hydrophobic segments.; Chapter 5 discusses the co-crystals of bipyridines with benzene-1,3,5-tricarboxylic acid, trimesic acid (TMA-H3) and compares with those from 3,5-pyridinedicarboxylic acid (PDA). These lead to a number of open 'chick-wire' hydrogen bond networks, with varying stoichiometry.; Finally in Chapter 6 we explore some other themes of organic hydrothermal crystallization through the results of a number of case studies, in which the technique can be applied to grow large organic crystals and examine issues of natural product and drug identification, stability and chiral resolution. (Abstract shortened by UMI.)...