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Unique properties of the two giant wheel-shaped molybdenum-oxides of the type {Mo(154)}≡[{Mo(2)}{Mo(8)}{Mo(1)}](14) (1) and {Mo(176)}≡[{Mo(2)}{Mo(8)}{Mo(1)}](16) (2) that have the same building blocks either 14 or 16 times, respectively, are considered and show a "chemical adaptability" as a new phenomenon regarding the integration of a large number of appropriate cations and anions, for example, in form of the large "salt-like" {M(SO(4))}(16) rings (M = K(+), NH(4)(+)), while the two resulting {Mo(146)(K(SO(4)))(16)} (3) and {Mo(146)(NH(4)(SO(4)))(16)} (4) type hybrid compounds have the same shape as the parent ring structures. The chemical adaptability, which also allows the integration of anions and cations even at the same positions in the {Mo(4)O(6)}-type units of 1 and 2, is caused by easy changes in constitution by reorganisation and simultaneous release of (some) building blocks (one example: two opposite orientations of the same functional groups, that is, of H(2)O{Mo=O} (I) and O={Mo(H(2)O)} (II) are possible). Whereas Cu(2+) in [(H(4)Cu(II)(5))Mo(V)(28)Mo(VI)(114)O(432)(H(2)O)(58)](26-) (5 a) is simply coordinated to two parent O(2-) ions of {Mo(4)O(6)} and to two fragments of type II, the SO(4)(2-) integration in 3 and 4 occurs through the substitution of two oxo ligands of {Mo(4)O(6)} as well as two H(2)O ligands of fragment I. Complexes 3 and now 4 were characterised by different physical methods, for example, solutions of 4 in DMSO with sophisticated NMR spectroscopy (EXSY, DOSY and HSQC). The NH(4)(+) ions integrated in the cluster anion of 4 "communicate" with those in solution in the sense that the related H(+) ion exchange is in equilibrium. The important message: the reported "chemical adaptability" has its formal counterpart in solutions of "molybdates", which can form unique dynamic libraries containing constituents/building blocks that may form and break reversibly and can lead to the isolation of a variety of giant clusters with unusual properties.

The new Mannich bases bis(1,4-diphenylthiosemicarbazide methyl) phosphinic acid H 3 L 1 and bis(1, 4-diphenylsemicarbazide methyl) phosphinic acid H 3 L 2 were synthesised from the condensation of phosphinic acid, formaldehyde with 1,4-diphenyl thiosemicarbazide and 1,4-diphenylsemicarbazide, respectively. Monomeric complexes of these ligands, of general formulae K 2 [Cr III (L n )Cl 2 ], K 3 [Mn II (L n )Cl 2 ] and K[M(L n )] (M = Co(II), Ni(II), Cu(II), Zn(II) or Hg(II); n = 1, 2), are reported. The mode of bonding and overall geometry of the complexes were determined through physico-chemical and spectroscopic methods. These studies revealed octahedral geometries for the Cr(III), Mn(II) complexes, square planar for Co(II), Ni(II) and Cu(II) complexes and tetrahedral for the Zn(II) and Hg(II) complexes.

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The new Schiff base phthaldihyde-bis(4-methyl-3-thiosemicarbazone) (PHMTSC) was synthesized from the condensation of phthaldihyde with 4-methyl-3-thiosemicarbazide. Monomeric complexes of this ligand, of general formulae [M(PHMTSC-2H ? )], are reported. The mode of bonding and overall geometry of the complexes were determined through physicochemical and spectroscopic methods. These studies revealed square planar geometries for the Ni(II) and Cu(II) complexes, and tetrahedral geometry for the Cd(II) complex. The kinetics of the reactions between PHMTSC and all the various metal salts has been determined by stopped-flow spectrophotometry. In all cases, the reactions are complete on the second's timescale. The reactions exhibit a first-order dependence on the concentration of metal salt and a first-order dependence on the concentration of PHMTSC. The thermodynamic and kinetic factors influencing the protonation state of the coordinated thiosemicarbazone are discussed.

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