Trimethyltin Groups Research Articles

Beta-sitosterol mitigates cognitive deficit and hippocampal neurodegeneration in mice with trimethyltin-induced toxicity.

The present study investigated the neural health benefit of beta-sitosterol (BSS) against trimethyltin (TMT)-induced neurodegeneration in mice. Forty male Institute of Cancer Research (ICR) mice were randomly divided into Sham-veh, TMT-veh, TMT-BSS50, and TMT-BSS100. A one-time intraperitoneal injection of 2.6 mg/kg of TMT was given to mice in TMT groups. Vehicle (veh), BSS 50 mg/kg or BSS 100 mg/kg were orally given for 2 weeks. Spatial learning and memory were evaluated. Brain oxidative status, hippocampal neuropathology, and reactive astrocytes were done. White matter pathology was also evaluated. The results indicated the massy effect of TMT on induced motor ability and spatial memory deficits in accordance with increased neuronal degeneration in Cornus ammonis (CA) 1, CA3, and dentate gyrus (DG) and internal capsule white matter damage. TMT also induced the reduction of reactive astrocytes in CA1 and DG. Brain's catalase activity was significantly reduced by TMT, but not in mice with BSS treatments. Both doses of BSS treatment exhibited improvement in motor ability and spatial memory deficits in accordance with the activation of reactive astrocytes in CA1, CA3, and DG. However, they successfully prevented the increase of neuronal degeneration in CA1 found only with the BSS dose of 100 mg/kg, and it was indicated as the effective dose for neuroprotection in the vulnerable brain area. This study demonstrated mitigative effects of BSS against motor ability and memory deficits with neural health benefits, including a protective effect against CA1 neurodegeneration and a nurturing effect on hippocampal reactive astrocytes.

Benefits of Erinacines from Different Cultivate Formulas on Cognitive Deficits and Anxiety-Like Behaviour in Mice with Trimethyltin-Induced Toxicity.

We investigated the neurological effects of the varied erinacine composition of different mycelia cultures in mice with trimethyltin (TMT)-induced neurodegeneration. Forty male ICR mice were randomly divided into five groups of Sham-veh, TMT-veh, TMT-EME, TMT-EMR and TMT-EME/R. The TMT groups received 2.6 mg/kg one-time intraperitoneal injections of TMT. Oral dosages of 200 mg/kg erinacine combination from each Hericium erinaceus mycelia (EM) cultivated formula (100% eucalyptus wood [E], 100% rubber wood [R], or 40% eucalyptus wood/60% rubber wood [E/R]) were given for two weeks. Spatial learning, memory, flexibility, and anxious behaviour were evaluated alongside brain tissues' oxidative status and histological analyses. Erinacine composition from EME/R exhibited significant positive effects on spatial learning, memory, flexibility, and anxiety (p < 0.05). These findings emerged concurrently with the significant mitigation of hippocampal lipid peroxidation, CA1 hippocampal, cortical neuron, and corpus callosum white matter degeneration (p < 0.05). These neurological benefits were associated with the EME/R composition of erinacine A, C, D, G, H, I, K and R. The best neuroprotective effect against TMT-induced neurodegeneration in mice is offered by the EME/R erinacine composition according to its anti-lipid peroxidation, its nurturing effect on neuronal and white matter, and mitigation of behavioural deficits.

THE EFFECT OF TUMERIC RHIZOME (CURCUMA LONGA L) ON RADIAL ARM MAZE AND PASSIVE AVOIDANCE TEST IN TRIMETILINE-INDUCED RAT MODELS

Backround : Oxidative stress can cause death of hippocampal cells associated to the deficit of learning and memory function. Turmeric rhizome contains curcuminoid which has antioxidant activity that can prevent oxidative stress, thus it was expected to prevent the deficit of learning and memory function on trimethyltin (TMT)-induced rat models. Objectve : This study aimed to determine the effect of turmeric rhizome extract on cognitive learning and memory fuction which was tested using radial arm maze and passive avoidance tests on Wistar rats injected with TMT. Methods : A total of 30 Wistar rats, male, 8-12 weeks of age were divided into 6 groups. The first (normal) group was given CMC-Na, the second (TMT) group was given CMC-Na, the third-the fifth groups were given turmeric rhizome extract (TRE) orally in the dosage of 120mg/kgBW (TRE120), 240 mg/kgBW (TRE240) and 480 mg/kgBW (TRE480), respectivelly. The sixth (P500) group was given piracetam in the dosage of 500 mg/kgBW. Treatments were given for 8 days orally. At day-9th, excluding the first group, all rats were injected with 12 mg/kgBW TMT solution intraperitoneally. One day after TMT injection, the cognitive learning and memory function was measured using radial maze and passive avoidance tests. The datas of cognitve function tests were analyzed statistically by ANOVA test followed by LSD test at significance level 0.05. Results : The results of radial maze and passive avoidance tests showed that the TRE240 group was not statistically significant different with TMT group(p>0.05). However there were significant difference between TRE120 and TMT groups, as well as between TRE480 and TMT groups (p 0.05). Conclusion : It can be concluded that the administration of 480 mg/kgBW of TRE can improve cognitive learning and memory function of Wistar rats injected by TMT.

The crystal structure of “bis(trimethyltin)-1,3,4-thiadiazole-2,5-dithiolate” – different bonding of the two trimethyltin groups

Abstract [(CH3)3Sn]2S2(C2N2S) is monoclinic, space group P21 /c, a = 10.492(5), b = 12.257(6), c = 12.691(6) Å, β = 95.86(1)°. The zigzag chain structure of the coordination polymer can be derived by the structure correlation method. The starting point is a monomolecular symmetric bis(trimethyltin)-1,3,4-thiadiazole-2,5-dithiolate (Me3SnS)2 (C2N2S): The first of the Me3SnS moieties, bound to the atom C5 of the heterocyclus, remains tetrahedral, whereas the other, bound to C2, is transformed through the N3 atom of the neighbouring ring to a trigonal bipyramid S···(Me3Sn)···N. The three C atoms and the Sn atom of this Me3Sn group are nearly coplanar and form the equatorial plane. With the N3 atom of the starting molecule, an equivalent linking to the other neighbour takes place. The resultant plane ribbons run parallel to the crystallographic b-axis. The analysis of the bond distances and angles reveals that the regular trigonal bipyramid almost exactly represents the transition state along a chemical reaction pathway for a nucleophilic SN2 displacement at tetrahedrally coordinated tin.

Reaction of the Si8O20(SnMe3)8 Building Block with Silyl Chlorides: A New Synthetic Methodology for Preparing Nanostructured Building Block Solids

A series of silicate based “building block” (bb) materials has been synthesized via the reaction of the cubic, spherosilicate Si8O20(SnMe3)8 with the chlorosilanes HSiCl3, Me2SiCl2, and SiCl4. The resulting materials are amorphous, porous, high surface area matrices composed of intact Si8O20 building blocks that are cross-linked together through a series of siloxane linkages formed from the reaction of trimethyltin groups on the spherosilicate precursor and the silyl chloride groups. These siloxane-based linkages provide chemically robust, covalent connections between building blocks. The distribution of chemically distinct linking groups may be influenced by manipulating initial stoichiometries, changing solvents, varying temperature, and using different linking silyl chlorides. General procedures for preparing silicate platforms having linking groups with specific connectivities to surrounding building blocks in the matrix are described. The synthetic strategy for preparing the building block matrices d...

Systemic Administration of Atipamezole, a Selective Antagonist of Alpha-2 Adrenoceptors, Facilitates Behavioural Activity but does not Influence Short-term or Long-term Memory in Trimethyltin-intoxicated and Control Rats

NIITTYKOSKI M., R. LAPPALAINEN, J. JOLKKONEN, A. HAAPALINNA, P. RIEKKINEN Sr and J. SIRVIÖ. Systemic administration of atipamezole, a selective antagonist of alpha-2 adrenoceptors, facilitates behavioural activity but does not influence short-term or long-term memory in trimethyltin-intoxicated and control rats. NEUROSCI BIOBEHAV REV 22(6) 735–750, 1998.—The present study used trimethyltin (TMT)-intoxicated rats as a model for the behavioural syndrome seen after neuronal damage to the limbic system. Behavioural assessments indicated increased locomotor activity and reduced number of groomings in an open-arena task in TMT-intoxicated (6.6 mg/kg as a free base) rats, as has been found previously. A novel finding was the severe deficit in swimming to a visible platform in the water maze task, with reduced swimming speed at the beginning of the training period. During the reacquisition phase of a radial arm maze task, TMT-intoxicated rats made more short-term and long-term memory errors, and their behavioural activity was increased in comparison with controls. The administration of atipamezole (300 μg/kg), a selective antagonist of α 2-adrenoceptors, enhanced locomotor activity compared to saline-treated rats, but these effects did not differ between the TMT group and their controls. Atipamezole did not enhance short-term or long-term memory in either TMT or control groups. Taken together, the present data indicate that TMT intoxication is a model for global dementia rather than for a specific loss of relational memory. Previous studies on the neurochemical effects of TMT and the alleviation or prevention of neurotoxicity of TMT are reviewed.

(Ketoprofenato)trimethyltin(IV)

In the title compound, [Sn(CH3)3(C16H13O3)], the Sn atom has fivefold coordination involving three methyl C atoms defining the equatorial plane of a trigonal bipyramid and two O atoms from two carboxylate groups occupying the axial positions. The Sn—C bond lengths [2.106 (6), 2.110 (5) and 2.116 (5) Å] are very similar. The two carboxylate O atoms have notably different distances to the metal atom [2.184 (3) and 2.433 (4) Å], with an O—Sn—O angle of 174.0 (1)°. Bidentate bridging of the carboxylate ligands via trimethyltin groups forms a polymeric structure.

ChemInform Abstract: Oxy‐ and Thio‐Phosphorus Acid Derivatives of Tin(IV). The Crystal and Molecular Structure of O‐Methylmethylphosphatotriphenyltin(IV).

Abstract O-Methylmethylphosphatotriphenyltin(IV) (II) is synthesized by treating stoichiometric amounts of O,O′-dimethylmonothiophosphatotriphenyltin(IV) (I) with mercury. The negative 119Sn chemical shift in solution relative to tetramethyltin for I corresponds to higher than four coordination (at tin) in solution. The values of the 119Sn Mossbauer isomer shift for I and II confirm the presence of tin as tin(IV). The magnitudes of the quadrupole splitting and the ratios of the QS to the IS of both compounds reveal that tin is higher than four coordinated. The solid state structure of II was determined by X-ray diffraction. The compound crystallized in the trigonal space group R 3 with a, b 31.433(15), c 10.259(3) A, V 8778.2 A3, Z = 18, Dx 1.56 g cm−3 at 138 K. In the solid state compound II exists as a highly symmetric cyclic hexamer in which planar trimethyltin(IV) groups are axially bridged by O-P-O linkages. The geometry about tin is trigonal bipyramidal with an axial O-Sn-O angle of 177.1(2)° and average C-Sn-C angle of 120.0(2)°. The structure of the hexameric ring is linear at tin but bent at phosphorus with an O-P-O angle of 117.1(2)°.

Oxy- and thio-phosphorus acid derivatives of tin(IV). The crystal and molecular structure of O-methylmethylphosphatotriphenyltin(IV)

O-Methylmethylphosphatotriphenyltin(IV) (II) is synthesized by treating stoichiometric amounts of O, O′-dimethylmonothiophosphatotriphenyltin(IV) (I) with mercury. The negative 119Sn chemical shift in solution relative to tetramethyltin for I corresponds to higher than four coordination (at tin) in solution. The values of the 119Sn Mössbauer isomer shift for I and II confirm the presence of tin as tin(IV). The magnitudes of the quadrupole splitting and the ratios of the QS to the IS of both compounds reveal that tin is higher than four coordinated. The solid state structure of II was determined by X-ray diffraction. The compound crystallized in the trigonal space group R 3 with a, b 31.433(15), c 10.259(3) Å, V 8778.2 Å 3, Z = 18, D x 1.56 g cm −3 at 138 K. In the solid state compound II exists as a highly symmetric cyclic hexamer in which planar trimethyltin(IV) groups are axially bridged by O-P-O linkages. The geometry about tin is trigonal bipyramidal with an axial O-Sn-O angle of 177.1(2)° and average C-Sn-C angle of 120.0(2)°. The structure of the hexameric ring is linear at tin but bent at phosphorus with an O-P-O angle of 117.1(2)°.

The crystal and molecular structure of trimethyltin(IV) chloride, a chlorine-bridged, linear polymer

The crystal and molecular structure of trimethyltin(IV) chloride has been determined by the heavy-atom technique, and refined to a final R value of 0.041 for 1375 independent reflections (2θ < 53°; Mo- K a radiation I > 2σ( I)) recorded at 138 ± 2 K on a Nonius CAD-4 counter diffractometer. The crystals are monoclinic with space group I2/ c; a 12.541(8), b 9.618(11), c 11.015(11) Å, β 92.62(7)°, Z = 8, D calcd 1.994 g cm −3. The needle crystals are composed of polymeric chains of chlorine atoms bridging non-planar trimethyltin(IV) units at unequal (2.430(2) and 3.269(2) Å) distances. The zig-zag chains are bent at chlorine (angle SnCl ▪Sn 150.30(9)°), but nearly linear at tin (angle ClSn ▪Cl 176.85(6)°) to describe a distorted trigonal bipyramidal geometry at tin with the trimethyltin groups eclipsed. The interchain d(Sn ▪Cl) distances are greater than 4.1 Å. The angles carbon—tin—carbon (mean 117.1(3)°) are larger than tetrahedral, while the angles carbon—tin—chlorine (mean 99.9(2) Å) are smaller, in accord with isovalent hybridization principles, but more severely distorted than in the gas-phase, monomeric structure. The tin—chlorine distance of 2.430(2) Å is also longer than in the gas phase monomer, and the intermolecular contact of 3.269 Å is shorter than in other organotin chloride bridged systems (sum of Van der Waals radii 3.85 Å).

ChemInform Abstract: CRYSTAL STRUCTURE OF POLYMERIC TRIS(TRIMETHYLTIN)CHROMATE HYDROXIDE

Crystals of the title compound are orthorhombic, space group Pbca, a= 20·85(2), b= 11·55(2), c= 16·58(2)A(at ca. –30 °C), Z= 8. The structure was determined at ca. –30 °C from diffractometer data by direct methods and refined by full-matrix least-squares to R 0·045 for 488 unique observed reflexions. The structure consists of a complicated network polymer. There are three crystallographically independent and approximately planar tri-methyltin groups, and in each case, approximately trigonal bipyramidal co-ordination of the tin atom is completed by two axial oxygen atoms. Each oxygen atom in the chromate group is also bonded to tin, and the hydroxide group bridges two trimethyltin groups and is probably hydrogen bonded to one of the chromate oxygens. The two tin atoms linked by the hydroxide group have similar co-ordination geometries, with short Sn–O(H)[2.l4(3) and 2·17(4)A] and long Sn–O(Cr)[2·48(5) and 2·51(4)A]. The two oxygen atoms responsible for the long Sn–O bonds make the shortest two Cr–O bond lengths [1·61(4) and 1·56(4)A]. Other bond lengths and angles are : Sn–O, 2·16(4) and 2·29(4); Cr–O, 1·78(4) and 1·70(4); mean Sn–C, 2·13 A; mean C–Sn–C, 119; mean O–Sn–O, 176; mean Cr–O–Sn, 144; and Sn–O–Sn, 136(2)°.

The crystal structure of N-(trimethylstannyl)- N-nitromethylamine

The crystal structure of Me 3SnN(Me)NO 2 has been determined by single crystal X-ray diffraction. The crystals are monoclinic, P2 1/ c, with a 12.52(2), b 9.91(2), c 14.34(2) Å, β 98.6(1)°, Z 8. Planar trimethyltin groups are linked by planar N-nitromethylamine groups to form infinite Sn(Me 3)N(Me)N(O) OSn(Me 3) chains in the Y axis direction. There are two sets of crystallographically non-equivalent chains, but the bond lengths and angles agree within experimental error. The coordination of tin is approximately trigonal bipyramidal, with axial nitrogen and oxygen. Mean bond lengths are: SnC, 2.16; SnN, 2.33; NC, 1.45; NN, 1.29; NO, 1.24; and OSn, 2.39 Å.

Crystal structure of polymeric tris(trimethyltin) chromate hydroxide

Crystals of the title compound are orthorhombic, space group Pbca, a= 20·85(2), b= 11·55(2), c= 16·58(2)A(at ca. –30 °C), Z= 8. The structure was determined at ca. –30 °C from diffractometer data by direct methods and refined by full-matrix least-squares to R 0·045 for 488 unique observed reflexions. The structure consists of a complicated network polymer. There are three crystallographically independent and approximately planar tri-methyltin groups, and in each case, approximately trigonal bipyramidal co-ordination of the tin atom is completed by two axial oxygen atoms. Each oxygen atom in the chromate group is also bonded to tin, and the hydroxide group bridges two trimethyltin groups and is probably hydrogen bonded to one of the chromate oxygens. The two tin atoms linked by the hydroxide group have similar co-ordination geometries, with short Sn–O(H)[2.l4(3) and 2·17(4)A] and long Sn–O(Cr)[2·48(5) and 2·51(4)A]. The two oxygen atoms responsible for the long Sn–O bonds make the shortest two Cr–O bond lengths [1·61(4) and 1·56(4)A]. Other bond lengths and angles are : Sn–O, 2·16(4) and 2·29(4); Cr–O, 1·78(4) and 1·70(4); mean Sn–C, 2·13 A; mean C–Sn–C, 119; mean O–Sn–O, 176; mean Cr–O–Sn, 144; and Sn–O–Sn, 136(2)°.

N.M.R. investigation of molecular motions in trimethyltin fluoride

Molecular motions of trimethyltin fluoride in the solid state have been studied by continuous wave and pulsed n.m.r. methods. The trimethyltin group rotates about its chain axis at high temperatures. This result with relatively free methyl group rotation even at 77 K supports the previously proposed structure in which there are parallel, planar trimethyltin groups.

Fragmentation and rearrangement processes in the mass spectra of perhalogeno-aromatic compounds. Part V. Pentafluorophenyl derivatives of tin and related compounds

The mass spectra of the compounds (C6F5)4–nSnRn(n= 1–3; R = Ph, Bu, and Me), [Me3Sn]2C6X4(X = F and Cl) and some related compounds have been studied. The basic features of the spectra are correlated with the nature and number of the hydrocarbon groups, and in the second type of compound, with the nature of the halogen and the ring position of the trimethyltin groups. In general, the mass spectra of compounds of the first type vary markedly with differing hydrocarbons, while increasing the hydrocarbon content shows no unusual features in the spectra. In compounds of the second type, the differences in the spectra of the fluorinated and chlorinated compounds are less obvious than the differences observed in the spectra of the 1,2- and 1,4-isomers. Halogen transfers to tin are common throughout leading to both neutral and charged tin–halogen species.

Crystal structure of (Me3Sn)2N2C

The crystal structure of (Me3Sn)2N2C has been determined by single-crystal X-ray diffraction, and the absolute configuration established for the particular crystal employed. The crystals are hexagonal, space group P6422, a= 8·74(1), c= 14·28(2)A, Z= 3. The structure consists of an infinite helical network of planar trimethyltin groups linked by linear NCN units. The nitrogen atoms complete a trigonal-bipyramidal arrangement about tin, with Sn–N 2·47(1) and Sn–C (mean) 2·14(2)A. The Sn2NCNSn2 moieties have exact D2(222) symmetry with a dihedral angle of 68° between the two Sn2NC planes; C–N 1·24(2)A and angle SnNC 117·6(4)°. The structure can be considered to be intermediate between carbodi-imide, cyanamide, and ionic extremes.

The crystal structure of (Me3Sn)2N2C

The crystal structure of (Me3Sn)2N2C consists of an infinite helical network of planar trimethyltin groups linked by linear NCN units.

The crystal structure of trimethyltin isothiocyanate

The crystal structure of Me3SnNCS consists of zig-zag –S ⋯ Sn–NCS ⋯ Sn– chains, bent only at sulphur, with nearly planar trimethyltin groups.

Preparation and spectroscopic studies of dialkyltin hydroxide nitrate, trimethyltin nitrate and its monohydrate

The reaction between a dialkyltin oxide (alkyl = CH 3 or C 2H 5) and dilute nitric acid gives a new type of compound, the dialkyltin hydroxide nitrates R 2Sn(NO 3)(OH). These are stable, high-melting, crystalline substances, which are soluble in water and in methanol but insoluble in non-polar solvents. Their infrared spectra indicate that the oxygen atoms of the OH and NO 3 groups are coordinated strongly with the tin atoms. The reaction of trimethyltin hydroxide with dilute nitric acid yields trimethyltin nitrate monohydrate (m.p. 98–99°), the sublimation of which gives anhydrous trimethyltin nitrate (m.p. 140°). The anhydrous compound is hygroscopic and reverts to the monohydrate upon the absorption of moisture. In anhydrous trimethyltin nitrate it is suggested that the planar trimethyltin groups are bridged by NO 3 units. The most probable structure of trimethyltin nitrate monohydrate is one in which the bridged structure of the anhydrous compound is retained but with the water molecule located in the plane of the trimethyltin group and weakly coordinated to the tin atom.