In the title complex, [PdCl2(C12H22S3)]·0.8CH3CN, a potentially tridentate thioether ligand coordinates in a cis-bidentate manner to yield a square-planar environment for the Pd(II) cation [mean deviation of the Pd from the Cl2S2 plane = 0.0406 (7) Å]. Each square-planar entity packs in an inverse face-to-face manner, giving pairs with plane-to-plane separations of 3.6225 (12) Å off-set by 1.1263 (19) Å, with a Pd···Pd separation of 3.8551 (8) Å. A partial acetonitrile solvent molecule is present. The occupancy of this molecule was allowed to refine, and converged to 0.794 (10). The synthesis of the previously unreported 3,6,9-trithiabicyclo[9.3.1]pentadecane ligand is also outlined.

The structures of four neutral binuclear Zn-II complexes of the Schiff-base macrocycles formed by the [2 + 2] template condensation of 2,6-diformyl-4-methylphenol with 1,2-diaminoethane: [H2L1], 1,3-diaminopropane: [H2L2], 1,4-diaminobutane: [H2L3] and 2,6-diacetyl-4-methylphenol with 1,2-diaminoethane: [H2L4] have been determined. The complexes [Zn-2(L-1)(OAc)(2)].2CHCl(3),[Zn-2(L-2)(OAc)(2)].2CHCl(3) and [Zn-2(L-4)Cl-2] each contain two five coordinate Zn-II centres with each metal ion bound to the N2O2 donor set of the macrocyclic ligand and to an anion molecule. Two different coordination environments are observed in [Zn-2(L-3)(mu-OAc)(OAc)].CHCl3 which contains both a five- and a six-coordinate Zn-II centre, with one acetate bridging two metal ions and a monodentate acetate bound to the six-coordinate Zn-II ion. Significantly, the reaction of pre-formed macrocyclic ligands [H4L2](PF6)(2) and [H4L4](PF6)(2) with Zn(OAc)(2).2H(2)O affords [Zn-2(L-2)(mu-OAc)](PF6).MeCN and [Zn(H2L4)(MeCN)](PF6)(2), respectively. The former shows two five-coordinate Zn-II centres in which an acetate bridges both metal ions. In the latter complex the macrocyclic ligand binds only one five-coordinate Zn-II ion with a molecule of MeCN bound at an apical position.

The Robson compartmental macrocyclic ligand derived from the condensation of derivatives of 2,6-diformylphenol and diamines has been prepared for the first time in its free ligand form; competitive three-phase transport and two-phase extraction studies confirm high double-loaded selectivity for the binding and delivery of Cu(II).

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The Robson compartmental macrocyclic ligand derived from the condensation of derivatives of 2,6-diformylphenol and diamines has been prepared for the first time in its free ligand form; competitive three-phase transport and two-phase extraction studies confirm high double-loaded selectivity for the binding and delivery of Cu(II).

Reaction of 2,6-diformyl- and 2,6-diacetyl-4-methylphenol with a large excess of both NH2OH . HCl and CH3CO2K in EtOH affords high yields of 2,6-diformyl-4-methylphenol dioxime (2-hydroxy-5-methylbenzenedicarbaldehyde dioxime) (H3L1) and 2,6-diacetyl-4-methylphenol dioxime (H3L2), respectively. The crystal structure of (H3L2) shows intramolecular hydrogen bonding with long-range intermolecular pi-stacking interactions and an extended intermolecular hydrogen-bonding network. The binuclear complexes of Co-II, Ni-II and Cu-II-[Co-2(H2L1)(2)(MeOH)(2)(H2O)(2)]Cl-2. 2MeOH, [Ni-2(H2L1)(2)(H2O)(4)][ClO4](2). 2H(2)O and [Cu-2(H2L1)(2)(ClO4)(2)] respectively-derived from the dioxime ligand (H3L1) have been synthesized and characterised and their single-crystal structures determined. The structure of [Co-2(H2L1)(2)(MeOH)(2)(H2O)(2)](2+) shows each high-spin Co-II to be six-co-ordinate and bound to an N2O4-donor array presented by two dioxime ligands and axially co-ordinated H2O and MeOH molecules, the dioxime ligands co-ordinating via the imino N- and phenoxy O-donors. The structure of [Ni-2(H2L1)(2)(H2O)(4)](2+) shows two octahedrally co-ordinated Ni-II each with an N2O4 donor set similar to that in [Co-2(H2L1)(2)(MeOH)(2)(H2O)(2)](2+) except that the co-ordination sphere of each Ni-II is completed by axial ligation to two H2O molecules. The structure of [Cu-2(H2L1)(2)(ClO4)(2)] confirms N2O4 donation at CUII With two bidentate ClO4- anions, Cu ... O 2.51(2), 2.76(2) Angstrom, interacting with the metal centres on either side of the planar oxime-phenolate array. In all three complexes the two dioxime ligands are monodeprotonated at the phenolic oxygen, and the oximes are linked by hydrogen bonds, which results in a pseudo-macrocyclic framework. Magnetic susceptibility measurements on the complexes over the range 2.5-340 K confirm that the complexes are antiferromagnetically coupled with values for the magnetic exchange constant J of -6.9 +/- 0.1, -16.0 +/- 0.6, and -452 +/- 4 cm(-1) for [Co-2(H2L1)(2)(MeOH)(2)(H2O)(2)]Cl-2, [Ni-2(H2L1)(2)(H2O)(4)][ClO4](2) and [Cu-2(H2L1)(2)(ClO4)(2)] respectively.

The synthesis of a range of new compartmental macrocyclic complexes based on 2,6-diformyl and -diketo phenol groups is described. The metal-free ligands have been prepared and structurally characterised for the first time, and this has led to the synthesis of novel cubane and platinum-group metal complexes. The synthesis of related dithiophenolato-bridged compartmental complexes of Ni-II Cu-II and Zn-II has been achieved and the relevance of these species to metalloproteins is discussed.