Crystal engineering using bisphenols and trisphenols. Complexes with hexamethylenetetramine (HMTA): Strings, multiple helices and chains-of-rings in the crystal structures of the adducts of HMTA with 4,4'-thiodiphenol(1/1), 4,4'-sulfonyldiphenol(1/1), 4,4'-isopropylidenediphenol(1/1), 1,1,1-tris(4-hydroxyphenyl)ethane(1/2) and 1,3,5-trihydroxybenzene(2/3)

The 4,4/-bisphenols (1), X(C6H4OH)(2) [a, X = nil; b, X = O; c, X = S; d, X = SO2; e, X = CO; f, X = CH2; g, X = CMe2; h, X = C(CF3)(2)], when co-crystallized from alcoholic solutions with hexamethylenetetramine, (CH2)(6)N-4 (HMTA), form 1:1 adducts (4a)-(h). 4,4'-Thiodiphenol-hexamethylenetetramine (1/1) (4c), C12H10O2S.C6H12N4, and 4,4'-sulfonyldiphenol-hexamethylenetetramine (1/1), (4d), C12H10O4S.C6H12N4, are orthorhombic, Pmn2(1), (4c) a = 15.029 (2), b = 9.7954 (8), c = 5.9817 (11)Angstrom and (4d) a = 14.779 (2), b = 10.2558 (15), c = 5.9817 (8) Angstrom, with Z = 2, and the structures consist of zigzag chains comprising strings of alternating bisphenol and HMTA units, each lying across mirror planes and linked by O-H ... N hydrogen bonds. In addition, both (4c) and (4d) exhibit C-H ...pi(arene) hydrogen bonds with one CH2 group of the HMTA unit acting as a donor to two different arene rings; (4d) also exhibits multiple C-H ... O=S hydrogen bonds with three C-H bonds in each HMTA unit acting as donors towards a single sulfone O atom. 4,4'-Isopropylidenediphenol-hexamethylenetetramine (1/1), (4g), C15H16O2.C6H12N4, is monoclinic, C2/c, a = 25.093(6), b = 7.1742(13), c = 23.612(7)Angstrom, beta = 110.42(2)degrees, with Z = 8, and again the structure is built from chains of alternating bisphenol and HMTA units linked by O-H ... N hydrogen bonds, but these now form double helices around twofold rotation axes; the double helices are themselves Linked into sheets by C-H ... O hydrogen bonds. The trisphenol (2), CH3C(C6H4OH)(3), forms three adducts (5a)-(c) with HMTA, having trisphenol:HMTA ratios of 1:2 (5a), 2:3 (5b) and 1:1 (5c). 1,1,1-Tris(4-hydroxyphenyl)ethane-hexamethylenetetramine (1/2) (5a), C20H18O3 (C6H12N4)2, is orthorhombic, P2(1)2(1)2(1), a = 6.9928(10), b = 14.0949(15), c = 30.999(4)Angstrom, with Z = 4, and the trisphenol units and half the HMTA units form a triple helix around a 2(1) axis, in which each strand consists of alternating phenol and HMTA units, linked as usual by O-H ... N hydrogen bonds. The remaining HMTA units, which are external to the triple helix, are connected to it by O-H ... N hydrogen bonds and are formed into externally buttressing stacks. The triol (3), 1,3,5-C6H3(OH)(3), forms a 2:3 adduct (6) with HMTA. 1,3,5-Trihydroxybenzene-hexamethylenetetramine (2/3), (6), C6H6O3.(C6H12N4)(1.5), is monoclinic, C2/c, a = 23.598 (2), b = 7.136 (2), c = 19.445 (3) Angstrom, beta = 96.822(11)degrees, with Z = 8, and the dominant structural motif consists of centrosymmetric rings containing two molecules each of (3) and HMTA, connected by O-H ... N hydrogen bonds; these rings are themselves linked into a chain-of-rings by further HMTA units lying on twofold rotation axes. The hydrogen-bonding patterns are codified using the graph-set approach.