Co-crystallization of coordination compounds through second-coordination sphere interactions

The mononuclear complexes belonging to the [M(valXn)](0/+) family [H(2)valXn are bicompartmental ligands derived from o-vanillin and 1,2-or 1,3-diamines; M = Ni(II), Cu(II), Au(III)] can efficiently act as receptors towards various hydrogen bond donors. The co-crystallization processes between [Ni(valXn)] complexes and ammonium salts (NH(4)Z, Z(-) ClO4-; PF6-; C6H5NH3ClO4) led to different supramolecular arrangements in the crystals depending on the host : guest molar ratio used in reactions. For a 2 : 1 stoichiometry, supramolecular dimers were obtained in the crystals: 2[Ni(valen)]center dot NH(4)Z (Z(-) = ClO4-, 1a; Z(-) PF6-, 1b), 2[Ni(valphen)]center dot NH4ClO4 center dot CH3OH 1c, 2[Ni(valmen)]center dot C6H5NH3ClO4 3, while for a 1 : 1 stoichiometry a supercomplex with a quadruple deck architecture resulted: 4[Ni(valen)]center dot 3NH(4)ClO(4) 2. The co-crystallization of the Reinecke salt with mononuclear complexes from the [M(valXn)] family affords the following crystals: [Ni(valen)]2 center dot NH4[Cr (NCS)(4)(NH3)(2)]center dot CH3OH(4), [Ni(valdmpn)](2)center dot NH4[Cr(NCS)(4)(NH3)(2)]center dot 2H(2)O 5, and [Cu(valpn)]center dot NH4[Cr (NCS)(4)(NH3)(2)]center dot CH3CN 6, in which the [M(valXn)] complexes interact with the ammonium ions and ammonia ligands, resulting in supramolecular chains. The composition and the topology of the supramolecular chain can be changed by replacing the ammonium ion from the Reinecke salt with a cationic receptor, [Au(valpn)](+) : [Au(valpn)][Cr(NCS) 4(NH3) 2] 7 .