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The reactivity of 1,1'-bis(3-methyl-4-imidazolin-2-selone)methane ( L1 ) and 1,2-bis(3-methyl-4-imidazolin-2-selone)ethane ( L2 ) toward I 2 has been explored in MeCN under different experimental conditions and compared with that in CH 2 Cl 2 . The compounds [ L1' ](I) 2 ( I ), [ L1 I] n (I) n ( II ), [ L1 (μ-Se)](I) 2 ·1/2H 2 O ( III ), [ L1 I](I 3 )·2I 2 ( IV ), and [ L2 ](I) 2 ·MeCN ( V ) were obtained and characterized. X-ray diffraction analyses point out an ionic nature for these compounds, which is presumably favored by the polarity of the solvent used. In particular, [ L1 I] n (I) n ( II ) represents the first example of an iodonium complex of imidazoline-2-selone derivatives, while [ L1 (μ-Se)](I) 2 ·1/2H 2 O ( III ) represents a unique example of a dicationic [RSeSeSeR] triselane. Density functional theory calculations have allowed us to better understand the nature of the obtained compounds and to justify their formations in polarizing reaction conditions rather than in low polar solvents.

The speciation of the potential antitumor agent vanadocene dichloride ([Cp2VCl2], abbreviated with VDC) in the blood plasma was studied by instrumental (EPR, ESI-MS, MS-MS, and electronic absorption spectroscopy) and computational (DFT) methods. The behavior of VDC at pH 7.4 in aqueous solution, the interaction with the most important bioligands of the plasma (oxalate, carbonate, phosphate, lactate, citrate, histidine, and glycine among those with low molecular mass and transferrin and albumin between the proteins) was evaluated. The results suggest that [Cp2VCl2] transforms at physiological pH to [Cp2V(OH)2] and that only oxalate, carbonate, phosphate, and lactate are able to displace the two OH(-) ions to yield [Cp2V(ox)], [Cp2V(CO3)], [Cp2V(lactH(-1))], and [Cp2V(HPO4)]. The formation of the adducts with oxalate, carbonate, lactate, and hydrogen phosphate was confirmed also by ESI-MS and MS-MS spectra. The stability order is [Cp2V(ox)] ≫ [Cp2V(CO3)] > [Cp2V(lactH(-1))] > [Cp2V(HPO4)]. No interaction between VDC and plasma proteins was detected under our experimental conditions. Several model systems containing the bioligands (bL) in the same relative ratio as in the blood samples were also examined. Finally, the speciation of VDC in the plasma was studied. The results obtained show that the model systems behave as the blood plasma and indicate that when V concentration is low (10 μM) VDC is transported in the bloodstream as [Cp2V(ox)]; when V concentration is high (100 μM) oxalate binds only 9.2 μM of [Cp2V](2+), whereas the remaining part distributes between [Cp2V(CO3)] (main species) and [Cp2V(lactH(-1))] (minor species); and when V concentration is in the range 10-100 μM [Cp2V](2+) distributes between [Cp2V(ox)] and [Cp2V(CO3)].

The windmill-shaped hexanuclear copper(II) cluster {(H(2)O)(2)Cu(2)(mu(3)-(Ade)(4)[Cu(oda)(H(2)O)](4)}.6H(2)O (1-o) has been synthesized in aqueous medium by in situ core-controlled expansion of the neutral building block Cu(2)(mu(2)-N3,N9-Ade)(4)(H(2)O)(2) (2) with Cu(oda)(H(2)O) (3-o) (Ade = adeninato(1-) and oda = oxydiacetato(2-) ligands). Crystal data for 2-b (2.5H(2)O): triclinic, space group P(-)1; a = 9.374(1), b = 9.440(1), c = 10.326(1) A; alpha = 78.72(1), beta = 76.77(1), gamma = 63.51(1) degrees ; final R(1) = 0.059; T = 100(2) K. Crystal data for 1-o: monoclinic, space group P2(1)/n; a = 15.203(2), b = 10.245(1), c = 19.094(2) A; beta = 101.61(1) degrees ; final R(1) = 0.049; T = 293(2) K. The X-shaped hexanuclear molecule consists of a central core (2) and four terminal arms (3-o) linked together by bridging mu(3)-N3,N7,N9-Ade ligands. There are three crystallographic independent metal atoms (two terminals, one central). All Cu(II) atoms exhibit a 4 + 1 coordination, of which one is an aqua apical ligand. The basal coordination sets complete the CuN(4) + O or CuO(3)N + O chromophores for the central or terminal metal atoms, respectively. Thermal stability and spectral and magnetic properties were also studied. Analogous compounds to 1-o with tridentate or tripodal tetradentate ligands L(2-), instead of oda, have also been synthesized.