摘要:
IntroductionSince molecular crystals are excellent supramolecular assemblies,1we use crystallisation and crystal packing analysis to investigate crystal supramolecular motifs. The bidentate ligands 2,2′-bipyridyl (bipy) and 1,10-phenathroline (phen), in their complexes, are able to engage in offset-face-to-face (OFF) and edge-to-face (EF) motifs, similar to those well known for phenyl groups.2Concerted action of these EF and OFF motifs leads to multiple aryl embraces, as principal supramolecular motifs. Complexes [M(bipy)3]zform the sixfold aryl embrace (6AE) shown inFig. 1(a),3while bis- and tris-phen complexes more commonly form the parallel fourfold aryl embrace (P4AE), shown inFig. 1(b).4,5The 6AE is comprised of six ligands engaged in a concerted cycle of six EF interactions, while the P4AE is comprised of one OFF and two EF motifs.The sixfold aryl embrace (6AE) commonly formed between two [M(bipy)3] complexes, and the parallel fourfold aryl embrace (P4AE) commonly formed between two [M(phen)3] complexes.Another phase of our investigations involves inorganic functionalities containing atoms of high atomic number, and high dispersion attractions, with a focus on iodine and polyiodides. In previous papers we have described the crystallisation and crystal packing analysis of dimorphs of [CuI(phen)2]I3,6of trimorphs of [Fe(phen)3]I12,7of [M(phen)3]I7(M = Mn, Fe),8and of [Fe(phen)3]I14and [Fe(phen)3]I18.9These systems combine the supramolecularity of M–phen complexes, and of polyiodides, and the occurrence of polymorphism in two systems indicates a balance of the energies of (a) the embraces between the complex cations, (b) the polyiodide associations, and (c) the associations of the complex cations and the polyiodide ions. The [Fe(phen)3]2+–polyiodide crystal system is particularly rich, yielding a total of 13 crystalline compounds, ranging from [Fe(phen)3]I4to [Fe(phen)3]I18.10In all of these a strong feature is the complementary orthogonality of the ligand planes in the complexes and of segments in the polyiodide ions, with Ixchains lying facial and edge-peripheral to phen ligands.In this paper we report the crystallisation and crystal supramolecularity of [Fe(phen)3]I8, and of [Mn(phen)3]I8. The crystal structures are very different, and this pair of compounds is another candidate for substitutional polymorphism.11,12
ISSN:1466-8033
DOI:10.1039/b008381j
出版商:RSC
年代:2000
数据来源: RSC