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C6H18ClN3O7S, trigonal, P31c (no. 159), a = 8.3990(14) Å, b = 8.3990(14)∘, c = 9.6208(17) Å, V = 587.76(17) Å3, Z = 2, Rgt(F) = 0.0497, wRref(F2) = 0.1404, T = 300.15 K.

A study was conducted on the complex formation of vanadium(IV) with cis-inositol (ino) and the corresponding trimethyl ether 1,3,5-trideoxy-1,3,5-trimethoxy-cis-inositol (tmci) in aqueous solution and in the solid-state. The results indicated the formation of three distinct isomers of the non-oxo complex [[V[(H-[3.sub.ion]).sub.2]].sup.2-] in weakly basic solution, which is not observed for the vanadium(IV)/tmci system.

A specific cis- and trans- effect for the 1H NMR signal of a H-C-N(R2)-Co-O(R)-H substructure has been described. The different behavior can readily be seen in an NMR titration experiment, and represents an efficient tool for the structure elucidation of such molecules.

Research has been conducted on the hydrated potassium salt. The preparation of this compound has been carried out and its crystal structure has been investigated.

Research has been conducted on the Cu (super)II complex. The interaction of this complex with the 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol ligand has been examined in both solid state and in solution and the phosphoesterase activity of the produced complexes has been tested.

The synthesis of a series of trinuclear lanthanoid complexes of 1,3,5-triamino-1,3,5-trideoxy-cis-inositol with a unique, sandwich-type cage structure was described. Magnetic susceptibility calculations and spectroscopic techniques were used to characterize the trinuclear complexes. Experimental results revealed extremely weak antiferromagnetic coupling interactions among the three Gd centers. It was also found that the stability of the lanthanoid complexes increases monotonically as the ionic radius of the metal center decreases.

The trinuclear {Gd3(H(sub -3)taci)2(H2O)6}3+ was characterized in aqueous solution via multiple field 17O nuclear magnetic resonance and electron paramagnetic resonance spectroscopy. The water exchange on {Gd3(H(sub -3)2taci)2(H2O)6}3+ had more associative properties and was approximately 70 times slower compared to the Gd(III) aqua ion. The observed low rotational correlation of the complex was attributed to the spherical structure, with the large hydrophobic surface inhibiting the formation of a substantial hydration sphere.

X-ray structural characterization, Raman spectroscopic measurements and quantum chemical calculations were employed in examining the reactivity and structure of [Mo3-mu3S-(muS2)3]4+ complexes. A significant reduction of the stretch resonance frequency was revealed by the Raman data. Calculations also indicated a substantial electron density release to the cation from the anion for the dimeric S2- derivative manifested by decreased net atomic charges.

An analysis was conducted to determine the crystal structures and stability constants of the taci complexes with the divalent MnII, FeII and CoII and analyze the redox properties of the three complexes. Electron paramagnetic resonance spectroscopy, potentiometric titrations and polarographic and cyclic measurements were utilized and performed to determine the crystal structures and stability constants of taci ligand and the complexes' redox properties. Results revealed that partially of dissociated taci ligand would result in the formation of an asymmetric complex after oxidation which is relevant in understanding the complexes' redox properties.

Chemical research using single-crystal X-ray analysis has established the structure for trichloride salts of [Fe(all-cis-2,4,6-trimethoxycyclohexane-1,3,5-triamine)2](super 3+). The low-spin d5 electron configuration of the iron(III) hexamine complex [Fe(1,2-ethanediamine)3](super 3+) exhibits low magnetic stability. [Fe(all-cis-2,4,6-trimethoxycyclohexane-1,3,5-triamine)2](super 3+) is chemically inert.

The reaction of (N(CH3)sub4)OH with FeCl3 and thme in a methanolic medium gives (N(CH3)4)2(OFe6(H-3thme)3(OCH3)3Cl6).2Hsub2O, where thme = 1,1,1-tris(hydroxymethyl)ethane. The structure has three methoxo bridges, which link two Fe(III) units to six terminally coordinating Cl- ligands. Variable temperature magnetic susceptibility values show antiferromagnetic coupling for the hexanuclear complex core in a singlet ground state. The Fe-mu6-O-Fe interactions are unusually large, which are explained using molecular orbital calculations at the extended Huckel level.

Fusion of NbS2Cl2 and KNCS followed by the dissolution of this melt in water produces Nb-NCS complexes that undergo replacement reaction of NCS by bidentate 1,1-dithioacid ligands to yield (Nb2(mu-S2)2)4+ complexes. X-ray analysis, ESR and mass spectra help the structural characterization of these complexes. (Cp2Fe)PF6 oxidizes Nb2S4(Et2NCS2)4 to produce ferrocene and a paramagnetic cluster cation.

Combination of aqueous solutions of taci and MX2 salts produce solid compounds consisting of the complexes (Cd(taci)2)2+, (Ca (taci)2(H2O)2)2+, (Sr(taci)2(H2O)3)2+ and (Ba(taci)(H2O)3)2+. (Mg(taci)2)2+ reveals a nearly regular MgO6 octahedron. A major elongation along a pseudo-3-solid axis is evident for the CdN6 octahedron in (Cd(taci)2)2+.

The preparation, characterization and X-ray structure of two trinuclear lead(II) and bismuth(III) complexes were reported. It was shown that 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci) is a powerful ligand for Pb(II) and Bi(III). Three Pb and three Bi atoms are bound to the three asymmetric sites of one taci molecule. The nuclear magnetic resonance spectra of the two compounds are in agreement with the idealized symmetry of C3v for the Pb(II) complex and D3h for the Bi(III) complex. Moreover, the most intense peaks in the two mass spectra were (Pb3(taci)(glycerol) - 5H)+ and (Bi3(taci)2 - 8H)+.

The complex 1,3,5-triamino-1,3,5-trideoxy-cis-inositol with Ni(II), Cu(II) and Zn(II) was investigated. These were obtained through the reaction of aqueous solutions containing the metal as bromide or nitrate with the free ligand. The three compounds formed were isomorphous and crystallized in the centrosymmetric space group Cmcm. The taci was found to be an effective chelator for Ni(II). Taci-metal complexes exhibited high stability constants contrary to taci's low affinity for H1+. The equatorial arrangement of the three amino groups reamins unless the two ligands interact with a metal.

The synthesis of OFe6(OCH3)18Na2(CH3OH)6 leads to its characterization and comparison with analogous systems. The complex is formed by allowing a CH3OH solution of dry FeCl3 and NaOCH3 to stand for a few days. X-ray diffraction studies reveal an oxygen core coordinated to six Fe(III) atoms in a distorted octahedral sphere, the Fe(III) atoms interlinked by 12 methoxides and ended by another six methoxides. Each of the sodium ions is coordinated to three methoxide bridges and three methanols. The similarity between its OFe6 core and that of its THME analogue leads to the possibility of a generalized core model for Fe(III) alkoxide complexes.

Studies of two hexairon(III) clusters containing a mu6-oxo bridge reveal that the unusual bridging mode causes weak antiferromagnetic exchange-coupling interactions between the metal centers with J trans and J cis values of 19(2) and 9(1) per cm, respectively. The studies may be useful in the search for magneto-structural correlations in oxo-bridged polyiron aggregates.

The various mechanisms involved in the characteristic spin-orbit induced [super 1]H([CH.sub.2]) chemical shifts that are induced upon the deprotonation of group 9 polyamine complexes are discussed. The heavier metal centers are shown to exhibit larger spin-orbit effects.

The reaction of [V(IV)O](super 2+) ion with the facially coordinating triol ligands taci was studied. A variety of new, remarkable stable non-oxo vanadium (IV) complexes were characterized.

The novel organometallic aqua complex [(Co)(sub 3)Mn(H2O)(sub 3)](super +1) is obtained through hydrolysis of the analogous acetone complex. The kinetic of water exchange is studied for a Mn(super I)-aqua complex.

Research has been conducted on CO) (sub)3 Re (super)I (H (sub)2 O) (sub)3] (super)+. The authors report the results of kinetic investigation of the water exchange process on this compound carried out via the use of (super)17 O NMR.

The title compound, [Ni(C10H8N2)3](C9H5N4O)2·2H2O, crystallizes as a racemic mixture in the monoclinic space group C2/c. In the crystal, the 1,1,3,3-tetracyano-2-ethoxypropenide anions and the water molecules are linked by O—H···N hydrogen bonds, forming chains running along the [010] direction. The bpy ligands of the cation are linked to the chain via C—H···π(cation) inter­actions involving the CH3 group. The inter­molecular inter­actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots. [ABSTRACT FROM AUTHOR]

In the title compound, [Fe(C11H11N3)2](C10N6), the FeII cation is coordinated by two bis(pyridin-2-yl)methanamine (dipa) ligands and has crystallographic twofold symmetry. There are deviations from ideal octahedral geometry due to the steric requirements of the ligands. The polynitrile 1,1,3,3-tetracyano-2-(dicyanomethylidene)propane-1,3-diide (tcpd2-) dianion is disordered about an inversion center and is not coordinated to the Fe atom. The anion is not planar but has a propeller shape. In the crystal, weak N--H...N interactions between the amine H atoms of the dipa ligands and two nitrile groups of the anion form an alternating chain of cations and anions related by the C-centering of the unit cell. [ABSTRACT FROM AUTHOR]