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Three organotin (IV) derivatives PhPO3HSnBu2Cl, SnBu2Ph2PO2Cl×3/2H2O, Sn(PhPO3)Cl2×2H2O obtained on allowing PhPO3H2 or propylammonium PhPO3H to react with SnBu2Cl2, SnCl2×2H2O and two adducts [(C6H5CH2)2NH2]3O2C(CH2)2PO3×3SnPh3Cl, [CyNH3(HO2POCH2-N(CH2CO2H)2]2×3SnCl4.2H2O×NH4Cl obtained on allowing (C6H5CH2)NH2)3O2C(CH2)2PO3 or [CyNH3(HO2POCH2-N(CH2 CO2H)2]2 and SnPh3Cl or SnCl2×2H2O to react in ethanolic media have been characterized by elemental analyses, infrared and Mossbauer techniques. The suggested structures, while considering the anionic counterpart, are discrete, dimeric, double and triple metallic components or of infinite chain types, the anion behaving as a monochelating, a bichelating or a bidentate ligand. In OH containing structures, when extra hydrogen bonds are considered, supramolecular architectures may be obtained.

Four new adducts catena-O,O′-glutaratotriphenylstannate, [(Me4N)2O2C(CH2)3CO2×4SnPh3Cl] (1), [(Me4N)2O2C(CH2)3CO2×3SnPh3Cl] (2), [(SnPh3)2O2C(CH2)3CO2×SnPh3Cl] (2′) and [(Cy2NH2)2O2C(CH2)3CO2×SnPh3Cl] (3), have been isolated from the reactions carried out in solution. The compounds have been characterized by FT-IR and Mössbauer spectroscopies except for 2’ whose structure is proposed on the basis of FT-IR data. Overall, the spectra studies sheew existence of several caracteristic bands such as υ (C=O), υ (CO2–), υ (Sn–O), υ (Sn–Cl), vibrations of glutarate ions, and the intense doublet showing the presence of phenyl groups. In the solid state, the suggested structures are discrete or of infinite chain. In this work, the geometry at Sn centers, trigonal bipyramidal or tetrahedral, is ascertained by the Mössbauer parameters. The glutarate ions exhibit a monodentate, tridentate or tetradentate coordination behavior towards the Sn atoms.  

Four new carboxyalkylphosphonate SnR2 residue (R = Me, Ph, Bu) containing adducts and derivatives i.e. {(Cy2NH2)3(O2CCH2PO3)(SnBu2Cl2)} (1), {[(SnMe2Cl)(O2CCH2PO3H2)]4[Cy2NH2Cl]} (2), {(Me4N)(SnPh2Cl)[O2C(CH2)2 PO3H](SnPh2)[O2C(CH2)2PO3H]} (3) and {(Cy2NH2)2(O2CCH2PO3H)(SnPh2Cl2)2} (4), have been synthesized from one-pot reactions carried out in solution. All compounds have been investigated by spectral techniques (infrared and Mossbauer). The spectral studies have evidenced presence of several characteristic bands, especially υ (C=O), υ (OH), υ (CO2- ), υ (PO32- ) vibrations coming from carboxyalkylphosphonate ions, with wide absorption due to the NH2 groups coming from the dicyclohexylammonium counter ion (for 1, 2 and 4) and the intense doublet which show the presence of phenyl groups (for 3 and 4). In the solid state, the proposed structures are discrete or of infinite chain however hydrogen bonding patterns may occur. Event in this investigation is the presence, for compound 3, of two types of arrangement at Sn centers viz. an octahedron and a trigonal bipyramidal whose presence are ascertained by the Mossbauer parameters. The neutral or acidic carboxyalkylphosphonate ions exhibit a diversity of coordination behavior towards the Sn atoms: monochelating (carboxylate and phosphonate O-donor), monochelating through the carboxylate and unidentate coordinating O-donor through the phosphonic acid or acidic phosphonate, bichelating with chelations from carboxylate and acidic phosphonate, and unidentate from both the carboxylate and phosphonic acid.

Eight new adducts and derivatives have been synthesized and studied by infrared. Discrete, layered or infinite chain structures are suggested with an oxalate behaving as a monodentate, bidentate, monochelating or bichelating ligand, the environment around the tin centres being tetrahedral, cis trigonal bipyramidal or octahedral. In all the studied compounds, supramolecular architectures may be obtained when intermolecular hydrogen bonds are considered.

Two MX2 (M = Ni, Zn; X = Cl, Br) dimethyl N-cyanodithioiminocarbonate compounds and one CrCl2 triphenylphosphine oxide complex were isolated and elucidated by single crystal X-ray crystallography. NiCl2[(CH3S)2C═NC≡N]2 (1) features inversion-related hydrogen bonded dimers linked into chains interacting through C-H···Cl growing layers along [110] whose junction into a 3D structure is enabled by H-bonds. ZnBr2[(CH3S)2C═NC≡N]2 (2) also exhibits inversion-related H-bonded dimers. In contrast with 1, the structure of 2 comprises chains along [110], connected via C-H···Br and C-H···S into a 2D layer along [-110]. CrCl2(OPPh3)2 (3) obtaining undergone redox processes, oxidizing [CH3C(O)CH2PPh3]+ to form PPh3PO, and reducing Cr from CrVI to CrII. In the structure, each molecule is linked to height neighbors through H-bonds affording a 3D network.

Two MX2 (M = Ni, Zn; X = Cl, Br) dimethyl N-cyanodithioiminocarbonate compounds and one CrCl2 triphenylphosphine oxide complex were isolated and elucidated by single crystal X-ray crystallography. NiCl2[(CH3S)2C?NC=N]2 (1) features inversion-related hydrogen bonded dimers linked into chains interacting through C-H Cl growing layers along [110] whose junction into a 3D structure is enabled by H-bonds. ZnBr2[(CH3S)2C?NC=N]2 (2) also exhibits inversion-related H-bonded dimers. In contrast with 1, the structure of 2 comprises chains along [110], connected via C-H Br and C-H S into a 2D layer along [-110]. CrCl2(OPPh3)2 (3) obtaining undergone redox processes, oxidizing [CH3C(O)CH2PPh3]+ to form PPh3PO, and reducing Cr from CrVI to CrII. In the structure, each molecule is linked to height neighbors through H-bonds affording a 3D network.

The title polymer [HCO2Sn(C6H5)3]n was isolated by serendipitous from reaction in ethanol 96 % between bis-(monocyclohexyl ammonium) 2-carboxyethyl hydrogen phosphonate, (CyNH3)2[CO2CH2CH2PO2(OH)] and triphenyltin chloride, SnPh3Cl. The polymer crystallizes in the monoclinic space group P21/n with Z = 4, a = 14.7091 (18) Å, b = 15.4133 (19) Å, c = 14.7639 (18) Å, β = 94.242 (2)° and V = 3338.0 (7) Å3. The structure consists of an infinite chain propagating along the crystallographic a-axis direction with bidentate formate anions. The O2SnC3 core is organized into a trans-trigonal bipyramidal like-arrangement.

Hydrogen phosphonate anions and monocyclohexylammonium cations interacting through hydrogen bonds conduct to the formation of a salt namely monocyclohexylammonium hydrogen phosphonate. In this structure, hydrogen phosphonate anions are linked by pairs through O—H···O hydrogen bonds leading to anionic dimers. Each dimer is connected to its two neighbours through cations via N—H···O hydrogen bonds leading to infinite chains which are then connected by N—H···O hydrogen bonds giving rise to a layered structure. The phenyl phosphonates form dimers that are connected through an expended hydrogen bonding network involving the cations into a layer.

On allowing PhPO^sub 3^H^sub 2^ to react with SnPh^sub 3^Cl in ethanolic media, OC[OPOSnPh^sub 3^OEt]^sub 2^ is obtained by cetonization, desarylation and esterification, has been studied by infrared technic. A discrete structure has been suggested on the basis of infrared data, the anion behaving as a bidentate ligand, the environment around the tin centres being tertrahedral.

The determination of the growth and exploitation parameters of Liza dumerili is carried out by the length frequency analysis method. Samples are either obtained from landings from the Joal Fadiouth artisanal fishery supplemented by catches made in experimental fishing by a purse seine. The measurements included total length, total weight, eviscerated weight and gonad weight. The data were analyzed by the FISAT II software for biometric analysis which include asymptotic length and growth coefficient (K) among others. For statistical analysis we used Past software for naturalists. The results obtained showed isometric isometry with b = 3. The growth parameters estimated using the von Bertallanfy equation gave the following results for the asymmetric length L∞ = 39.55 cm and a growth coefficient k = 0.37 year-1. According to the methods used, the instantaneous mortality is Z = 2.61an-1, the fishing mortality F = 1.99 yr-1 and the natural mortality M = 0.62 yr-1. Virtual population analysis showed that L. dumerili is overexploited in the area with an exploitation rate E = 0.76. Juveniles are the most affected by fishing pressure. In the management of local fisheries, management measures specific to the species are required.