Abstract The scarcity of studies concerning diestertin(IV) dithiocarbamate complexes led us to in... more Abstract The scarcity of studies concerning diestertin(IV) dithiocarbamate complexes led us to investigate the spectroscopic and structural properties of [(RO2CCH2CH2)2Sn(MDTC)2] (R = Me (1) or Et (2); MDTC = morpholinodithiocarbamate). The reaction of [(MeO2CCH2CH2)2SnCl2] with sodium morpholinodithiocarbamate (NaMDTC) in CHCl3 afforded (1), while the transesterification reaction of (1) with EtOH in the presence of dmso yielded (2). Both diestertin(IV) complexes were characterized by elemental analysis, FTIR and multinuclear (1H, 13C and 119Sn) NMR spectroscopy, and single-crystal X-ray diffraction. Our X-ray structural analysis revealed that (1) and (2) exhibit a distorted pentagonal bipyramidal coordination geometry. In both cases, the apical positions are occupied by ester groups while the equatorial plane displays two bidentate morpholinodithiocarbamate ligands and one intramolecular C O⋯Sn interaction. The O⋯Sn distances amount to 2.632 (1) and 2.618 A (2). According to our supramolecular analysis, the crystal arrangement of each product is assembled by weak C–H⋯O and C–H⋯S hydrogen bonds. Finally, a DFT study of the six- and seven-coordinate forms of (1) and (2) allowed an upper-bound estimate of the intramolecular C O⋯Sn interaction energy, −3.7 kcal mol−1.
The reaction of ammonium pyrrolidinedithiocarbamate with SnPh2Cl2 and SnPh3Cl produced in good yi... more The reaction of ammonium pyrrolidinedithiocarbamate with SnPh2Cl2 and SnPh3Cl produced in good yield the compounds [Sn{S2CN(CH2)4}2{C6H5}2]·toluene (1) and Sn{S2CN(CH2)4}{C6H5}3 (2). They were fully characterised by multinuclear NMR [1H,13C{1H} and 119Sn{1H}] and 119Sn Mössbauer spectroscopies. In addition the structure of 1 was determined, and 2 was revised by X-ray crystallographic studies. Finally, thermal decomposition experiments were carried out for both compounds
Mn(iii)–porphyrin catalysts with electron-withdrawing substituents were designed to uncover elect... more Mn(iii)–porphyrin catalysts with electron-withdrawing substituents were designed to uncover electronic and structural aspects in the cycloaddition of CO2 with epoxides.
Abstract The reactions of SnR2Cl2 (R = Me, Bu or Ph) with sodium 4-phenylbutyrate, NaO2C(CH2)3Ph ... more Abstract The reactions of SnR2Cl2 (R = Me, Bu or Ph) with sodium 4-phenylbutyrate, NaO2C(CH2)3Ph (NaOPhb), yielded three organotin carboxylates, namely [{(Me2SnOPhb)2O}2] (1), [Bu2Sn(OPhb)2] (2) and [{PhSn(O)OPhb}6] (3). Complexes (1) and (2) have been spectroscopically authenticated by FT-IR, 119Sn Mossbauer, and 1H, 13C{1H} and 119Sn{1H} NMR techniques. In addition, the crystallographic structures of (1)–(3) have been determined by X-ray diffraction measurements. Complex (1) displays two signals in the solution 119Sn NMR spectrum corresponding to the exo (δ −176.3) and endocyclic (δ −188.4) SnMe2 moieties, whereas (2) exhibits only one 119Sn resonance (δ −148.1). The crystallographic characterization of (1) confirms the centrosymmetric tetranuclear stannoxane structure and the existence of the exo and endocyclic SnMe2 moieties in the both distorted trigonal bipyramidal and octahedral environment, respectively. Complex (2) crystallises as a monomer in which the Sn(IV) cation lies at the centre of a distorted octahedron. The bonding scheme in (3) outlines a hexanuclear drum-like structure comprising two six-membered (–Sn–O–)3 stannoxane rings. The supramolecular arrangements of (1)–(3) result from noncovalent interactions, namely Sn⋯O (1) and (2), C–H⋯π (1), and C–H⋯O (1)–(3). Finally, antifungal activities of all organotin derivatives have been screened against Candida albicans (ATCC 18804), Candida tropicalis (ATCC 750), Candida glabrata (ATCC 90030), Candida parapsilosis (ATCC 22019), Candida lusitaniae (CBS 6936), and Candida dubliniensis (clinical isolate 28). Complex (2) exhibited the best biocide activity amongst the three organotin products.
Abstract The scarcity of studies concerning diestertin(IV) dithiocarbamate complexes led us to in... more Abstract The scarcity of studies concerning diestertin(IV) dithiocarbamate complexes led us to investigate the spectroscopic and structural properties of [(RO2CCH2CH2)2Sn(MDTC)2] (R = Me (1) or Et (2); MDTC = morpholinodithiocarbamate). The reaction of [(MeO2CCH2CH2)2SnCl2] with sodium morpholinodithiocarbamate (NaMDTC) in CHCl3 afforded (1), while the transesterification reaction of (1) with EtOH in the presence of dmso yielded (2). Both diestertin(IV) complexes were characterized by elemental analysis, FTIR and multinuclear (1H, 13C and 119Sn) NMR spectroscopy, and single-crystal X-ray diffraction. Our X-ray structural analysis revealed that (1) and (2) exhibit a distorted pentagonal bipyramidal coordination geometry. In both cases, the apical positions are occupied by ester groups while the equatorial plane displays two bidentate morpholinodithiocarbamate ligands and one intramolecular C O⋯Sn interaction. The O⋯Sn distances amount to 2.632 (1) and 2.618 A (2). According to our supramolecular analysis, the crystal arrangement of each product is assembled by weak C–H⋯O and C–H⋯S hydrogen bonds. Finally, a DFT study of the six- and seven-coordinate forms of (1) and (2) allowed an upper-bound estimate of the intramolecular C O⋯Sn interaction energy, −3.7 kcal mol−1.
The reaction of ammonium pyrrolidinedithiocarbamate with SnPh2Cl2 and SnPh3Cl produced in good yi... more The reaction of ammonium pyrrolidinedithiocarbamate with SnPh2Cl2 and SnPh3Cl produced in good yield the compounds [Sn{S2CN(CH2)4}2{C6H5}2]·toluene (1) and Sn{S2CN(CH2)4}{C6H5}3 (2). They were fully characterised by multinuclear NMR [1H,13C{1H} and 119Sn{1H}] and 119Sn Mössbauer spectroscopies. In addition the structure of 1 was determined, and 2 was revised by X-ray crystallographic studies. Finally, thermal decomposition experiments were carried out for both compounds
Mn(iii)–porphyrin catalysts with electron-withdrawing substituents were designed to uncover elect... more Mn(iii)–porphyrin catalysts with electron-withdrawing substituents were designed to uncover electronic and structural aspects in the cycloaddition of CO2 with epoxides.
Abstract The reactions of SnR2Cl2 (R = Me, Bu or Ph) with sodium 4-phenylbutyrate, NaO2C(CH2)3Ph ... more Abstract The reactions of SnR2Cl2 (R = Me, Bu or Ph) with sodium 4-phenylbutyrate, NaO2C(CH2)3Ph (NaOPhb), yielded three organotin carboxylates, namely [{(Me2SnOPhb)2O}2] (1), [Bu2Sn(OPhb)2] (2) and [{PhSn(O)OPhb}6] (3). Complexes (1) and (2) have been spectroscopically authenticated by FT-IR, 119Sn Mossbauer, and 1H, 13C{1H} and 119Sn{1H} NMR techniques. In addition, the crystallographic structures of (1)–(3) have been determined by X-ray diffraction measurements. Complex (1) displays two signals in the solution 119Sn NMR spectrum corresponding to the exo (δ −176.3) and endocyclic (δ −188.4) SnMe2 moieties, whereas (2) exhibits only one 119Sn resonance (δ −148.1). The crystallographic characterization of (1) confirms the centrosymmetric tetranuclear stannoxane structure and the existence of the exo and endocyclic SnMe2 moieties in the both distorted trigonal bipyramidal and octahedral environment, respectively. Complex (2) crystallises as a monomer in which the Sn(IV) cation lies at the centre of a distorted octahedron. The bonding scheme in (3) outlines a hexanuclear drum-like structure comprising two six-membered (–Sn–O–)3 stannoxane rings. The supramolecular arrangements of (1)–(3) result from noncovalent interactions, namely Sn⋯O (1) and (2), C–H⋯π (1), and C–H⋯O (1)–(3). Finally, antifungal activities of all organotin derivatives have been screened against Candida albicans (ATCC 18804), Candida tropicalis (ATCC 750), Candida glabrata (ATCC 90030), Candida parapsilosis (ATCC 22019), Candida lusitaniae (CBS 6936), and Candida dubliniensis (clinical isolate 28). Complex (2) exhibited the best biocide activity amongst the three organotin products.
Uploads
Papers by Claudio Donnici