title: Hybrid host-guest complexes: directing the supramolecular structure through secondary host-guest interactions.
abstract: A set of four hybrid host-guest complexes based on the inorganic crown ether analogue [H12W36O120]12- ({W36}) have been isolated and characterised. The cluster anion features a central rigid binding site made up of six terminal oxygen ligands and this motif allows the selective binding of a range of alkali and alkali-earth-metal cations. Here, the binding site was utilised to functionalise the metal oxide-based cavity by complexing a range of protonated primary amines within the recognition site. As a result, a set of four hybrid organic-inorganic host-guest complexes were obtained whereby the interactions are highly directed specifically within this cavity. The guest cations in these molecular assemblies range from the aromatic 2-phenethylamine (1) and 4-phenylbutylamine (2) to the bifunctional aromatic p-xylylene diamine (3) and the aliphatic, bifunctional 1,6-diaminohexane (4). Compounds 1-4 were structurally characterised by single-crystal X-ray diffraction, elemental analysis, flame atomic absorption spectroscopy, FTIR and bond valence sum calculations. This comparative study focuses on the supramolecular effects of the amine guest cations and investigates their structure-directing effects on the framework arrangement arising by locking the protonated amines within the cavity of the {W36} cluster. It was shown that parts of the organic guest cation protrude from the central binding cavity and the nature of this protruding organic "tail" directs the solid-state arrangement of compounds 1-4. Guest cations with a hydrophobic phenyl tail result in an antiparallel assembly of {W36} complexes arranged in a series of pillared layers. As a consequence, no direct supramolecular interactions between {W36} clusters are observed. In contrast, bifunctional guest cations with a secondary amino binding site act as molecular connectors and directly link two cluster units thus locking the supramolecular assembly in a tilted arrangement. This direct linking of {W36} anions results in the formation of an infinite supramolecular scaffold.
authors.affiliation: WestCHEM, Department of Chemistry, The University of Glasgow, Glasgow G12 8QQ (UK), Fax: (+44) 141-330-4888.
authors.forename: Carsten
authors.initials: C
authors.lastname: Streb
authors.affiliation: WestCHEM, Department of Chemistry, The University of Glasgow, Glasgow G12 8QQ (UK), Fax: (+44) 141-330-4888.
authors.forename: Thomas
authors.initials: T
authors.lastname: McGlone
authors.affiliation: WestCHEM, Department of Chemistry, The University of Glasgow, Glasgow G12 8QQ (UK), Fax: (+44) 141-330-4888.
authors.forename: Oliver
authors.initials: O
authors.lastname: Brücher
authors.affiliation: WestCHEM, Department of Chemistry, The University of Glasgow, Glasgow G12 8QQ (UK), Fax: (+44) 141-330-4888.
authors.forename: De-Liang
authors.initials: DL
authors.lastname: Long
authors.affiliation: WestCHEM, Department of Chemistry, The University of Glasgow, Glasgow G12 8QQ (UK), Fax: (+44) 141-330-4888.
authors.forename: Leroy
authors.initials: L
authors.lastname: Cronin
references.citation: D.-L. Long, E. M. Burkholder, L. Cronin, Chem. Soc. Rev. 2007, 36, 105;
references.citation: L. Cronin, High Nuclearity Polyoxometalate Clusters in Comprehensive Coordination Chemistry 2, 7th ed., 2004, p. 1;
references.citation: M. T. Pope, A. Müller, Angew. Chem. 1991, 103, 56;
references.citation: Angew. Chem. Int. Ed. Engl. 1991, 30, 34;
references.citation: C. L. Hill, Chem. Rev. 1998, 98, 1.
references.citation: K. Wassermann, M. H. Dickman, M. T. Pope, Angew. Chem. 1997, 109, 1513;
references.citation: Angew. Chem. Int. Ed. Engl. 1997, 36, 1445;
references.citation: D.-L. Long, Y.-F. Song, E. F. Wilson, P. Kögerler, S.-X. Guo, A. M. Bond, J. S. J. Hargreaves, L. Cronin, Angew. Chem. 2008, 120, 4456;
references.citation: Angew. Chem. Int. Ed. 2008, 47, 4384.
references.citation: L. Cronin, C. Beugholt, E. Krickemeyer, M. Schmidtmann, H. Bögge, P. Kögerler, T. K. K. Luong, A. Müller, Angew. Chem. 2002, 114, 2929;
references.citation: Angew. Chem. Int. Ed. 2002, 41, 2805.
references.citation: A. Müller, E. Beckmann, H. Bögge, M. Schmidtmann, A. Dress, Angew. Chem. 2002, 114, 1210;
references.citation: Angew. Chem. Int. Ed. 2002, 41, 1162.
references.citation: I. V. Kozhevnikov, Chem. Rev. 1998, 98, 171.
references.citation: J. T. Rhule, W. A. Neiwert, K. I. Hardcastle, B. T. Do, C. L. Hill, J. Am. Chem. Soc. 2001, 123, 12101.
references.citation: A. Müller, M. Luban, C. Schröder, R. Modler, P. Kögerler, M. Axenovich, J. Schnack, P. Canfield, S. Bud′ko, N. Harrison, ChemPhysChem 2001, 2, 517.
references.citation: A. Müller, P. Kögerler, A. W. M. Dress, Coord. Chem. Rev. 2001, 222, 193;
references.citation: L. Cronin, P. Kögerler, A. Müller, J. Solid State Chem. 2000, 152, 57.
references.citation: D. M. Way, A. M. Bond, A. G. Wedd, Inorg. Chem. 1997, 36, 2826;
references.citation: N. Fay, A. M. Bond, C. Baffert, J. F. Boas, J. R. Pilbrow, D.-L. Long, L. Cronin, Inorg. Chem. 2007, 46, 3502.
references.citation: P. J. S. Richardt, J. M. White, P. A. Tregloan, A. M. Bond, A. G. Wedd, Can. J. Chem. 2001, 79, 613;
references.citation: C. Streb, D.-L. Long, L. Cronin, Chem. Commun. 2007, 471.
references.citation: H. D. Zeng, G. R. Newkome, C. L. Hill, Angew. Chem. 2000, 112, 1841;
references.citation: Angew. Chem. Int. Ed. Engl. 2000, 39, 1772.
references.citation: F. Ogliaro, S. P. de Visser, S. Cohen, P. K. Sharma, S. Shaik, J. Am. Chem. Soc. 2002, 124, 2806;
references.citation: Y.-F. Song, H. Abbas, C. Ritchie, N. McMillian, D.-L. Long, N. Gadegaard, L. Cronin, J. Mater. Chem. 2007, 17, 1903.
references.citation: D.-L. Long, H. Abbas, P. Kögerler, L. Cronin, Angew. Chem. 2005, 117, 3481;
references.citation: Angew. Chem. Int. Ed. 2005, 44, 3415;
references.citation: Y.-F. Song, N. McMillan, D.-L. Long, J. Thiel, Y. Ding, H. Chen, N. Gadegaard, L. Cronin, Chem. Eur. J. 2008, 14, 2349-2354;
references.citation: H. N. Miras, D.-L. Long, P. Kögerler, L. Cronin, Dalton Trans. 2008, 214.
references.citation: K. F. Aguey-Zinsou, P. V. Bernhardt, U. Kappler, A. G. McEwan, J. Am. Chem. Soc. 2003, 125, 530.
references.citation: D. A. Judd, J. H. Nettles, N. Nevins, J. P. Snyder, D. C. Liotta, J. Tang, J. Ermolieff, R. F. Schinazi, C. L. Hill, J. Am. Chem. Soc. 2001, 123, 886.
references.citation: C. Streb, C. Ritchie, D.-L. Long, P. Kögerler, L. Cronin, Angew. Chem. 2007, 119, 7723;
references.citation: Angew. Chem. Int. Ed. Engl. 2007, 46, 7579;
references.citation: P. Kögerler, L. Cronin Angew. Chem. 2005, 117, 866; Angew. Chem. Int. Ed. 2005, 44, 844;
references.citation: Angew. Chem. Int. Ed. 2005, 44, 844.
references.citation: D. Hagrman P. J. Hagrman J. Zubieta, Angew. Chem. 1999, 111, 3359;
references.citation: Angew. Chem. Int. Ed. 1999, 38, 3165;
references.citation: S. S. Kuduva N. Avarvari M. Fourmigue, J. Chem. Soc. Dalton Trans. 2002, 3686.
references.citation: P. Mialane, A. Dolbecq, L. Lisnard, A. Mallard, J. Marrot and F. Secheresse, Angew. Chem. 2002, 114, 2504;
references.citation: Angew. Chem. Int. Ed. 2002, 41, 2398.
references.citation: T. Hori O. Tamada S. Himeno, J. Chem. Soc. Dalton Trans. 1989, 1491;
references.citation: S. Juraja, T. Vu, P. J. S. Richardt, A. M. Bond, T. J. Cardwell, J. D. Cashion, G. D. Fallon, G. Lazarev, B. Moubaraki, K. S. Murray, A. G. Wedd, Inorg. Chem. 2002, 41, 1072.
references.citation: M. T. Pope in Comprehensive Coordination Chemistry, Vol. 3 (Eds. G. Wilkinson, R. D. Gillard, J. A. McCleverty), Pergamon Press, 1987.
references.citation: D.-L. Long, P. Kögerler, L. J. Farrugia, L. Cronin, Angew. Chem. 2003, 115, 4312;
references.citation: Angew. Chem. Int. Ed. 2003, 42, 4180;
references.citation: D.-L. Long, P. Kögerler, L. J. Farrugia, L. Cronin, Dalton Trans. 2005, 1372.
references.citation: B. J. S. Johnson, R. C. Schroden, C. Zhu, A. Stein, Inorg. Chem. 2001, 40, 5972;
references.citation: M. Vasylyev, R. Popovitz-Biro, L. J. W. Shimon, R. Neumann, J. Mol. Struct. 2003, 656, 27.
references.citation: D.-L. Long, P. Kögerler, L. Cronin, Angew. Chem. 2004, 116, 1853;
references.citation: Angew. Chem. Int. Ed. 2004, 43, 1817;
references.citation: C. Fleming, D.-L. Long, N. McMillan, J. Johnson, N. Bovet, V. Dhanak, N. Gadegaard, P. Kögerler, L. Cronin, M. Kadodwala, Nat. Nanotechnol. 2008, 3, 229.
references.citation: D.-L. Long, D. Orr, G. Seeber, P. Kögerler, L. J. Farrugia, L. Cronin, J. Cluster Sci. 2003, 14, 313.
references.citation: H. Abbas, A. L. Pickering, D.-L. Long, P. Kögerler, L. Cronin, Chem. Eur. J. 2005, 11, 1071.
references.citation: H. Abbas, C. Streb, A. L. Pickering, A. R. Neil, D.-L. Long, L. Cronin, Cryst. Growth Des. 2008, 8, 635.
references.citation: J. J. Hastings, O. W. Howarth, J. Chem. Soc. Dalton Trans. 1992, 209.
references.citation: S. Himeno, I. Kitazumi, Inorg. Chim. Acta 2003, 355, 81.
references.citation: D.-L. Long, H. Abbas, P. Kögerler, L. Cronin, J. Am. Chem. Soc. 2004, 126, 13880.
references.citation: D.-L. Long, O. Brücher, C. Streb, L. Cronin, Dalton Trans. 2006, 2852.
references.citation: C. J. Pedersen, J. Am. Chem. Soc. 1967, 89, 7017.
references.citation: CCDC-691395 (1), 691396 (2), 691397 (3) and 691398 (4) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.