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Two novel classes of cavitand-based coordination cages 7a--j and 8a--d have been synthesized via self-assembly procedures. The main factors controlling cage self-assembly (CSA) have been identified in (i) a P--M--P angle close to 90 degrees between the chelating ligand and the metal precursor, (ii) Pd and Pt as metal centers, (iii) a weakly coordinated counterion, and (iv) preorganization of the tetradentate cavitand ligand. Calorimetric measurements and dynamic (1)H and (19)F NMR experiments indicated that CSA is entropy driven. The temperature range of the equilibrium cage-oligomers is determined by the level of preorganization of the cavitand component. The crystal structure of cage 7d revealed the presence of a single triflate anion encapsulated. Guest competition experiments revealed that the encapsulation preference of cages 7b,d follows the order BF(4)(-) > CF(3)SO(3)(-) >> PF(6)(-) at 300 K. ES-MS experiments coupled to molecular modeling provided a rationale for the observed encapsulation selectivities. The basic selectivity pattern, which follows the solvation enthalpy of the guests, is altered by size and shape of the cavity, allowing the entrance of an ancillary solvent molecule only in the case of BF(4)(-).

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Here we report on the synthesis and characterisation of four new complexes of the [2×2] M 4 II grid-type (M = Co, Fe, Zn) with oligopyridine-derived ligands. The presence of aminopyrazine and aminopyrimidine moieties at the edge of the ligands potentially enables the formation of infinite hydrogen-bonded multi-grid networks. The ligands were synthesised by subsequent stannylations and Stille-type coupling reactions. The complexes were obtained by self-assembly of the ligand with the metal salt. The single-crystal X-ray structure was determined for the Co complex 7 containing aminopyrimidine as the hydrogen-bonding moiety [P1 ; a =

A series of compounds possessing polyvalent iodine groups was prepared from onitroiodobenzene. Single crystal X-ray investigation revealed a strong interaction between iodine atom and one of the oxygen atoms of the nitro group. This interaction is strongest in trifluoroacetate of hydroxy(o-nitrophenyl)iodonium salt, which is formed from an iodosylarene and an acid being the first example of this new class of compounds. These compounds are also characterized by NMR-spectroscopy.

The synthesis and X-ray structures of three metal complexes with terpyridine-derived ligands that contain amino-pyrimidine and amino-pyrazine moieties are presented. They have been designed in view of directing their selfassembly into specific supramolecular arrays through molecular recognition interactions. The solid-state structures indeed reveal extensive hydrogen-bonded networks. The Co complex 4 a with PF 6 À counterions builds a two-dimensional infinite interwoven grid through strong double hydrogen bonds (d(N-H-N) 2.918 ± 3.018 ) between the amino groups and the N atoms of the rings, with all H-bonding sites saturated. Changing the anions to BF 4 À in 4 b leads to a similar infinite but partially broken grid with a quarter of the H-bonding sites unsaturated (d(N-H-N) 2.984 ± 3.206 ). In the case of the Zn complex 12 with triflate anions, half of the hydrogen bonds are formed. Only one of the two orthogonal ligands has hydrogen bonds (d(N-H-N) 3.082, 3.096 ) to the neighbouring complexes and thus builds linear, supramolecular, polymeric chains. These structural differences are mainly attributed to crystal-packing effects caused by the different anions. The data presented here may also be regarded as a prototype for the generation of organised arrays through sequential selfassembly processes.

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