Crystal and molecular structure of tris(ethylenethiourea)copper(I) sulphate and tris(tetramethylthiourea)copper(I) tetrafluoroborate [examples of trigonal planar copper(I) stereochemistry]

Abstract

The crystal structures of tris(ethy1enethiourea)copper (I) sulphate and tris(tetramethy1thiourea) copper-(I) tetrafluoroborate have been determined and both shown to contain CuQ) and three sulphur atoms in a planar arrangement.THE stereochemistry of copper( 1) is important not only because of its chemical interest, but also because of its relevance to oxidation-reduction in copper-containing en2ymes.l With soft ligands, e.g., sulphur, compounds with the same stoicheiometry may have different stereochemistry. Tris(thiourea) copper (I) tetrafluoroborate, [Cu-(tu),]BF,,, and tris-(NN'-dimethylthiourea)copper(I) tetrafluoroborate, [Cu(~-dmtu),]BF,,~ are sulphur-bridged dimers with tetrahedral CuI ; while tris(ethy1enethiourea)copper(1) sulphate and tris(tetramethylthiourea)copper(I) tetrafluoroborate are trigonal planar CuI monomers. Hence, the stereochemistry of CuI with "soft" atom donors is very flexible. We report here the crystal and molecular structure of the last two complexes.

Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study

“…Metal complexes with s-TU ligands have been reported for a number of metals such as copper [6,7], platinum [8], palladium [8], zinc and cadmium [8,9]. The s-TU derivatives have, as possible donor sites, the sulphur atom of the C-S group and the nitrogen atom of the NH, NHR or NRR' groups (where R=R'=alkyl or dialkyl groups).…”

X-ray diffraction study of copper(I) thiourea complexes formed in sulfate-containing acid solutions

“…The chemistry of thiourea in copper-ion-containing solutions is rather complex due to the formation of a number of Cu I complex species with different molecular structures (Vranka & Amma, 1966;Hanic & Durcanska  , 1969;Spofford & Amma, 1970;Weininger et al, 1972;Gash et al, 1973;Taylor et al, 1974;Grif®th et al, 1976;Ferrari & Gasparri, 1976;Grif®th et al, 1978). In acid solution complex species are positively charged and the molecular structure of crystallized complex salts depends on the nature of the counter ions.…”

“…(2000). B56, 993±997 complex salts have been reported mainly related to ClO 4 À , NO 3 À and Cl À as counter ions (Vranka & Amma, 1966;Hanic & Durcanska  , 1969;Spofford & Amma, 1970;Weininger et al, 1972;Gash et al, 1973;Taylor et al, 1974;Grif®th et al, 1976;Ferrari & Gasparri, 1976;Grif®th et al, 1978). For a sulfatecontaining solution, the structure of [Cu 4 (tu) 6 ](SO 4 ) 2 Á2H 2 O (Declercq et al, 1978;Van Meerssche et al, 1982b), [Cu 4 (tu) 7 ](SO 4 ) 2 ÁH 2 O (Bott et al, 1998) (Declercq et al, 1978), [Cu 2 (tu) 5 ](SO 4 )Á3H 2 O (Ferrari & Gasparri, 1976) Recent electrochemical and surface analysis data of copper surfaces in contact with aqueous dilute thiourea acid solutions have shown the formation of passive layers with different characteristics depending on the applied electric potential and thiourea concentration in the solution.…”

Syntheses and structures of [Ag(etu)3]2SO4 and [{Cu(etu)I}3] n (etu = ethylenethiourea): a new μ 3–S coordination mode for etu

“…A series of silver(I) and copper(I) complexes with etu and its N-alkyl derivatives has been reported. The ligands display terminal monodentate thione-S, 2 -S and 4 -S bridging coordination modes, with the former being dominant; mononuclear complexes with trigonal [3][4][5][6][7][8][9][10], and tetrahedral [11] …”