title: Three hexahydropyridopyrimidine-spiro-cyclohexanetriones: supramolecular structures generated by O-H...O, N-H...O, C-H...O and C-H...pi hydrogen bonds, and pi-pi stacking interactions.
abstract: 4',4'-Dimethyl-2-methylsulfanyl-3,4,5,6,7,8-hexahydropyrido[2,3-d]pyrimidine-6-spiro-1'-cyclohexane-2',4,6'-trione, C(15)H(19)N(3)O(3)S, (I), has a markedly polarized molecular-electronic structure, and the molecules are linked into a three-dimensional framework by a combination of N-H.O, C-H.O and C-H.pi hydrogen bonds. 8-Hydroxymethyl-4',4'-dimethyl-2-methylsulfanyl-3,4,5,6,7,8-hexahydropyrido[2,3-d]pyrimidine-6-spiro-1'-cyclohexane-2',4,6'-trione, C(16)H(21)N(3)O(4)S, (II), where the hydroxymethyl substituent is disordered over two sets of sites, has a much less polarized structure than (I); the molecules are linked by a combination of O-H.O and N-H.O hydrogen bonds into chains containing alternating R(2)(2)(8) and R(2)(2)(16) rings, and these chains are linked into sheets by a combination of a pi-pi stacking interaction and a C-H.O hydrogen bond. 8-Ethoxymethyl-2-methoxy-4',4'-dimethyl-3,4,5,6,7,8-hexahydropyrido[2,3-d]pyrimidine-6-spiro-1'-cyclohexane-2',4,6'-trione, C(18)H(25)N(3)O(5), (III), has an unpolarized electronic structure, and a combination of N-H.O, C-H.O and C-H.pi hydrogen bonds links the molecules into sheets.
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland.
authors.forename: John N
authors.initials: JN
authors.lastname: Low
authors.forename: George
authors.initials: G
authors.lastname: Ferguson
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.forename: Manuel
authors.initials: M
authors.lastname: Nogueras
authors.forename: Silvia
authors.initials: S
authors.lastname: Cruz
authors.forename: Jairo
authors.initials: J
authors.lastname: Quiroga
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell