Ph Sn Research Articles

Unsymmetrical Bicentric Organotin Lewis Acids {Me2N(CH2)3}Ph(X)Sn(CH2)nSnPh2X (X = F, I; n = 1, 3): Syntheses and Structures

The syntheses of the intramolecularly coordinated organotin compounds {Me2N(CH2)3}Ph(X)SnCH2SnPh2X (3, X = I; 4, X = F) and {Me2N(CH2)3}Ph(F)Sn(CH2)3SnPh2F (7) are reported. The compounds have been characterized by elemental analysis, electrospray mass spectrometry, 1H,1H DOSY (4), 13C, 19F, and 119Sn NMR spectroscopy, and single-crystal X-ray diffraction analysis. In the solid state, compound 4 is a head-to-tail dimer as a result of unsymmetrical Sn–F–Sn bridges, whereas compound 7 is a monomer with F→Sn intramolecular coordination, giving a six-membered ring. In solution, both 4 and 7 are monomeric. The reactions of both 4 and 7 with fluoride anion in CD2Cl2 have been investigated by variable-temperature 19F and 119Sn NMR spectroscopy.

Organotin(IV) complexes derived from proteinogenic amino acid: synthesis, structure and evaluation of larvicidal efficacy on Anopheles stephensi mosquito larvae

Five new organotin(IV) complexes of composition [Bz2SnL1]n (1), [Bz3SnL1H⋅H2O] (2), [Me2SnL2⋅H2O] (3), [Me2SnL3] (4) and [Bz3SnL3H]n (5) (where L1 = (2S)‐2‐{[(E)‐(4‐hydroxypentan‐2‐ylidene)]amino}‐4‐methylpentanoate, L2 = (rac)‐2‐{[(E)‐1‐(2‐hydroxyphenyl)methylidene]amino}‐4‐methylpentanoate and L3 = (2S)‐ or (rac)‐2‐{[(E)‐1‐(2‐hydroxyphenyl)ethylidene]amino}‐4‐methylpentanoate) were synthesized and characterized using 1H NMR, 13C NMR, 119Sn NMR and infrared spectroscopic techniques. The crystal structure of 2 reveals a distorted trigonal‐bipyramidal geometry around the tin atom where the oxygen atoms of the carboxylate ligand and a water ligand occupy the axial positions, while the three benzyl ligands are located at the equatorial positions. On the other hand, the analogous derivative of enantiopure L3H (5) consists of polymeric chains, in which the ligand‐bridged tin atoms adopt the same trans‐Bz3SnO2 trigonal‐bipyramidal configuration and are now coordinated to a phenolic oxygen atom instead of H2O. In 2, the OH hydrogen of the ketoimine substituent has moved to the nearby nitrogen atom while in the salicylidene derivative 5, the OH is located almost midway between the phenolic oxygen atom and the nitrogen atom of the CN group. For the dibenzyltin derivative 1, a polymeric chain structure is observed as a result of a long intermolecular Sn⋅⋅⋅O bond involving the exocyclic carbonyl oxygen atom from the tridentate ligand of a neighbouring tin‐complex unit. The tin atom in this complex has distorted octahedral coordination geometry. In contrast, the racemic dimethyltin(IV) complexes 3 and 4 display discrete monomeric structures with a distorted octahedral‐ and trigonal‐bipyramidal geometry, respectively. The structures show that the coordination mode of the Schiff base ligand depends primarily on the number of bulky benzyl ligands (R) at the tin atom, as indeed found in the structures of related complexes where R = phenyl. With three bulky R groups, the tridentate chelating O,N,O coordination mode is preferred, whereas with fewer or less bulky R ligands, only the carboxylate and hydroxy groups are involved, which leads to polymers. Larvicidal efficacies of two of the new tribenzyltin(IV) complexes (2 and 5) were assessed on the second larval instar of Anopheles stephensi mosquito larvae and compared with two triphenyltin(IV) analogues, [Ph3SnL1H]n and [Ph3SnL3H]n. The results demonstrate that the compounds containing Sn–Ph ligands are more effective than those with Sn–Bz ligands. Copyright © 2016 John Wiley & Sons, Ltd.

Cyclo-Stannasiloxanes Containing both Oxygen Atoms and Methylene Moieties within the Ring and Formation of Related Organotin Oxo Clusters

The syntheses of the 8-membered stannasiloxanes cyclo-[RR′SnOSi(Me2)CH2]2 (5, R = R′ = Ph; 6, R = R′ = t-Bu; 7, R = Me2N(CH2)3, R′ = Ph) is reported. These react with organoelement oxides, providing the novel metallasiloxanes cyclo-[Me2SiCH2(RR′)SnOMO] (8, R = R′ = Ph, M = t-Bu2Sn; 9, R = R′ = t-Bu, M = t-Bu2Sn; 10, R = Me2N(CH2)3, R′ = Ph, M = t-Bu2Sn; 11, R = Me2N(CH2)3, R′ = Ph, M = Ph2Ge). Among these, compound 11 is the first example of such species being composed of four different group 14 elements in the 6-membered-ring skeleton. On contact with moist air compound 8 surprisingly undergoes Sn–Ph bond cleavage, giving the diorganotinoxo cluster [PhSn(CH2Me2SiO)Sn(μ3-O)(μ-OH)t-Bu2]2 (12), which shows a ladder-type structure. The latter reacts with 2 molar equiv of t-Bu2SnO, affording the Sn6-diorganotin oxo cluster [t-Bu2(μ-OH)Sn(μ3-O)SnPh(CH2Me2SiO)Sn-t-Bu2(μ3-O)]2 (13). The compounds have been characterized by NMR spectroscopy, electrospray mass spectrometry, and in the case of compounds 5–7, 12, and 13 also by single-crystal X-ray diffraction analysis.

Avaliação química de queijos Minas artesanais frescos e curados em Uberaba, MG

The artisan Minas cheese is made by the use of raw milk, milk culture, natural rennet and salt, and its production, traditional, is a major source of income for small producers in the Minas State. With the need for information to enrich and deepen the knowledge of artisan Minas cheese, in particular chemical characteristics, was collected 24 samples of Minas cheese (12 fresh and 12 ripened cheese) in the city of Uberaba-MG for subsequent assessment of acidity, lactose, protein, sodium chloride, moisture and salt in moisture, nitrogen compounds of proteolysis of products and extension and depth of maturation. On average the results of acidity, lactose, protein, total nitrogen (NT), nitrogen soluble at pH 4.6 (SN pH 4.6) and soluble nitrogen in TCA 12% (SNTCA), sodium chloride, moisture, salt in moisture (S/M) for the artisanal cheese fresh and cured were respectively: 1.03/1.10%; 5,2g/100grams/ 4, 6g/100grams; 21.68/26.07%; 3.52/3.73%; 0.30/0.47%; 0.27/0.42%; 1.43%/1.98%, 47.4/32.81%, 2.86/6.37%. The extension (EM) and depth of maturation (DM) presented values equal to 8.51% and 7.61% for fresh cheeses and for cheeses ripened the values were 13.41% and 11.49, respectively. There was no significant difference between the values of acidity, lactose, protein and NT, however, significant difference for the moisture parameters, sodium chloride, S/U, NS pH4 .6, NSTCA, and DM between fresh cheese and ripened. The average values of nitrogen compounds, sodium chloride, S/U, EM and DM indexes were greater value in ripened cheeses. The moisture content of ripened cheeses were lower than the fresh cheese.

Advancement Towards Tin-based Anticancer Chemotherapeutics: Structural Modification and Computer Modeling Approach to Drug-Enzyme Interactions

Three new triphenyltin(IV) complexes, viz., triphenylstannyl 2-((E)-(4-hydroxy-3-((E)-((4-(methoxycarbonyl)phenyl)imino)methyl)phenyl)-diazenyl)benzoate (Ph(3)SnL(2)H: 2), methyl 2-((E)-(4-hydroxy-3-((E)-((4-(((triphenylstannyl)oxy)carbonyl)phenyl)imino)methyl)phenyl)diazenyl)benzoate (Ph(3)SnL(3)H: 3), and triphenylstannyl 2-((E)-(4-hydroxy-3-((E)-((4-(((triphenylstannyl)oxy)carbonyl)phenyl)imino)methyl)phenyl)diazenyl)benzoate ((Ph(3)Sn)(2)L(4)H: 4) were synthesized and characterized by spectroscopic ((1)H, (119)Sn NMR and IR) techniques in combination with elemental analysis. The (119)Sn NMR spectral data were recorded in a non-coordinating solvent and indicate tetrahedral coordination geometry in solution. In the solid state, a single-crystal X-ray diffraction analysis of the dinuclear complex (Ph(3)Sn)(2)L(4)H (4) revealed a monocapped tetrahedral coordination geometry with anisobidentate coordination modes of the carboxylate groups with average bond angles around the Sn atoms of 113.5 and 112.2°, respectively. In vitro cytotoxicity studies were performed with all three complexes 2-4, along with a previously reported parent aquatriphenylstannyl complex, 2-((3-formyl-4-hydroxyphenyl)diazenyl)benzoate (Ph(3)SnL(1)H.OH(2) (1)) across a panel of human tumor cell lines, viz., A498, EVSA-T, H226, IGROV, M19 MEL, MCF-7 and WIDR. The screening results were compared with those from related triphenyltin(IV) carboxylates containing (i) imino (11-16) and (ii) diazenyl frameworks (1, 5-10). In general, complexes 2-4 exhibited good cytotoxic activity and among them, compound 4 was found to be the best performer, particularly for EVSA-T and MCF-7 cell lines. Additionally, 4 scored better activity than cisplatin (2-15 folds), 5-fluorouracil and etoposide across a panel of cell lines. Docking studies indicated that the diazenyl and imino nitrogen atoms, and the oxygen atoms of triphenyltin ester, methyl ester and phenolic group play an important role for the complexation of the organotin compounds in the active sites of enzymes such as ribonucleotide reductase (pdb ID: 4R1R), thymidylate synthase (pdb ID: 2G8D), thymidylate phosphorylase (pdb ID: 1BRW) and topoisomerase II (pdb ID: 1QZR).

Synthetic, 119Sn NMR Spectroscopic, Electrochemical, and Reactivity Study of Organotin A3 Corrolates Including Chiral and Ferrocenyl Derivatives

Various R/Ar-functionalized tin 5,10,15-tris(pentafluorophenyl)corrolate derivatives are reported herein including the first ferrocenyltin corrolate species. The isopropyl, sec-butyl-, 2-methyl-n-butyl-, phenyl-, 2-thienyl-, and ferrocenyltin species have been prepared and characterized through (1)H, (13)C, and (119)Sn HMQC NMR spectroscopy, mass spectrometry, UV-vis and photoluminescent spectroscopy, and cyclic voltammetry studies. J(C/H-Sn) NMR spectroscopic couplings and ring-current effects (upfield shifting) were determined for the R-Sn axial hydrogen and carbon atoms. This report adds to older conceptually similar reports, by, i.e., Janson et al. (J. Am. Chem. Soc. 1969, 91, 5210) and Walker et al. (J. Am. Chem. Soc.1983, 105, 6923-6929), as discussed herein. Such NMR spectroscopic aspects are discussed for these model systems. Compound Sn-Ph bond cleavage was achieved by treatment with I(2).

Selective fluorometric detection of pyrophosphate by 3-hydroxyflavone-diphenyltin(iv) complex in aqueous micellar medium

3-Hydroxyflavonate-diphenyltin(IV) chloride (Ph(2)Sn(Ofl)Cl) was prepared and characterized structurally by single crystal X-ray diffraction. The compound possesses high fluorescence (λ(max) 464 nm with excitation at 400 nm) in neutral aqueous solutions containing 5 mM cetyltrimethylammonium chloride and does not lose the flavonol ligand even at high dilution. The fluorescence is selectively quenched by pyrophosphate (PPi) (linear range 0-5 μM, detection limit 0.1 μM). Determination of 1 μM PPi tolerates the presence of 100-fold excess of AMP, ADP, inorganic phosphate and acetate, and 10-fold excess of ATP. From concentration profiles of the quenching effect it is concluded that quenching occurs due to formation of the complex (Ph(2)Sn(Ofl))(3)PPi, which is transformed at higher PPi concentrations to a simple 1 : 1 complex Ph(2)Sn(Ofl)(PPi). No flavonol ligand exchange with PPi is observed. A series of related organotin(IV) complexes were prepared in situ by reacting 3-hydroxyflavone with Me(2)SnCl(2), PhSnCl(3) and n-BuSnCl(3). The derivatives of Me(2)SnCl(2) and PhSnCl(3) behave similarly to Ph(2)Sn(Ofl)Cl but with lower sensitivity to PPi. However, the n-butyltin(IV) derivative tentatively of the composition n-BuSn(Ofl)(2) undergoes fluorescence enhancement rather than quenching in the presence of PPi in the μM concentration range. The results of this study demonstrate that the use of metal flavonol complexes as optical sensors for anions is a promising approach.

A Versatile Solvent-Free Mechanochemical Route to the Synthesis of Heterometallic Dicyanoaurate-Based Coordination Polymers

The solid-state mechanochemical method was proved to be a fast, simple, and efficient route to the synthesis of heterometallic [Au(CN)(2)]-based coordination polymers. Thus, a series of mixed-metal complexes, such as KCo[Au(CN)(2)](3), KNi[Au(CN)(2)](3), Cu(H(2)O)(2)[Au(CN)(2)](2), and Zn[Au(CN)(2)](2), was obtained by grinding stoichiometric amounts of K[Au(CN)(2)] and transition metal(II) chlorides. This solid-state method rapidly yields pure dicyanoaurate-based compounds, also in cases when the aqueous solution synthesis leads to an unseparable mixture of products. In addition, in some cases, the solid state reaction was faster than the corresponding solvent-based reaction. This mechanochemical method can be applied also to main group metals to obtain various cyanoaurate-based heterometallic coordination polymers, such as Me(2)Sn[Au(CN)(2)](2) and Ph(3)Sn[Au(CN)(2)]. For the 2:1 mixture of K[Au(CN)(2)] and Me(2)SnCl(2), the dramatic enhancement of the reaction rate by the presence of a minor amount of water was noticed. In Ph(3)Sn[Au(CN)(2)], as was revealed by single-crystal X-ray diffraction, each Ph(3)Sn unit is linked to two others by two Au(CN)(2) bridges via Sn-N bonds to form an infinite cyanide-bridged chain. There are no Au···Au contacts between the chains due to the sterical hindrance of the phenyl groups. A dehydrated blue Co[Au(CN)(2)](2) complex was obtained during grinding or heating of the moderate-pink Co(H(2)O)(2)[Au(CN)(2)](2) complex. This complex displays a vapochromic response when exposed to a variety of organic solvents, as well as water and ammonia vapors.

Reactions of in situ generated hydrated organotin cations with chelating O,O- or O,N-ligands: a possible structure-directing influence of the organic substituent on tin

The reaction of [n-Bu(2)SnO](n) with 1,5-naphthalenedisulfonic acid tetrahydrate in a 1:1 stoichiometry followed by reaction with 2,2'-bipyridine-N,N'-dioxide (BPDO-I) afforded a 1D-coordination polymer [n-Bu(2)Sn(BPDO-I)(1,5-C(10)H(6)(SO(3))(2))](n) (1) where the disulfonate ligand acts as a bridging ligand between two tin centers. An analogous reaction involving [Ph(2)SnO](n) afforded a trihydrated O,O'-chelated diorganotin cation [{Ph(2)Sn(BPDO-I)(H(2)O)(3)}(2+)][C(10)H(6)(SO(3)(-))(2)]·2CH(3)OH (2·2CH(3)OH). Utilizing two equivalents of BPDO-I in this reaction resulted in the ionic complex [{Ph(2)Sn(BPDO-I)(2)(H(2)O)}(2+)][C(10)H(6)(SO(3)(-))(2)]·3H(2)O (3·3H(2)O). In 2 and 3 the sulfonate ligands are not present in the coordination sphere of tin. Reaction of [n-Bu(2)SnO](n) and 1,5-naphthalenedisulfonic acid tetrahydrate, followed by reaction with [bis(diphenylphosphoryl)methane (DPPOM)] resulted in the formation of, [{n-Bu(2)Sn(DPPOM)(2)(H(2)O)(1,5-C(10)H(6)(SO(3))(SO(3)(-))}]·H(2)O (4·H(2)O). Of the two coordinating groups present in DPPOM, only one P=O group is coordinated to the tin atom. The remaining P=O motif is free and is involved in intramolecular H-bonding with the tin-bound water molecule. Using [Ph(2)SnO](n) instead of [n-Bu(2)SnO](n) afforded the ionic complex [{Ph(2)Sn(DPPOM)(2)}(2+){1,5-C(10)H(6)(SO(3)(-))(2)}] (5) where the DPPOM functions as a chelating ligand. The reaction of [n-Bu(2)SnO](n) with 1,5-naphthalenedisulfonic acid tetrahydrate followed by addition of one equivalent of 8-hydroxyquinoline (8-HQ) in presence of triethylamine afforded the neutral dinuclear complex, [(H(2)O)(8-Q)n-Bu(2)Sn(μ-1,5-C(10)H(6)(SO(3))(2))n-Bu(2)Sn(8-Q)(H(2)O)] (6) where the two tin atoms are bridged by the disulfonate ligand. Compounds 1-6 are thermally stable as shown by their thermogravimetric analyses.

Preparation and structural characterization of nickel(II), cobalt(II), zinc(II) and tin(IV) complexes of the isatin Schiff bases of S-methyl and S-benzyldithiocarbazates

The molecular structures of the isatin Schiff bases of S-methyldithiocarbazate (Hisasme) and S-benzyldithiocarbazate (Hisasbz) have been determined by X-ray diffraction and their complexes of general formula [ML 2]· n(solvate) [M = Co 2+, Ni 2+, Zn 2+; L = anionic forms of Hisasme or Hisasbz; solvate = DMF, DMSO; n = 1, 2] and [Sn(L)Ph 2Cl]· nMeOH ( n = 0, 1) have been synthesized and characterized by a variety of physicochemical techniques and X-ray diffraction. The bis-ligand complexes, [Ni(isasbz) 2]·2DMSO and [Co(isasme) 2]·DMF have a six-coordinate, distorted octahedral geometry with the two uninegatively charged tridentate ONS ligands coordinated to the metal ions meridionally via the amide O-atoms, the azomethine nitrogen atoms and the thiolate sulfur atoms. By contrast, the crystal structure of [Zn(isasbz) 2]·2DMF shows a four-coordinate distorted tetrahedral geometry with the two Schiff bases coordinated as NS bidentate ligands via the azomethine nitrogen atoms and the thiolate sulfur atoms. Steric constraints of the rigid tridentate ligands lead to unusual ‘pseudo-coordination’ of the O-donors which occupy sites close to the metal but too distant to be considered as true coordinate bonds. The crystal structures of the tin(IV) complexes [SnLPh 2Cl]· nMeOH (L = isasme and isasbz; n = 0, 1) also show that the Schiff bases act as monoanionic bidentate NS chelating agents coordinating the tin(IV) ion via the azomethine nitrogen atoms and the thiolate sulfur atoms, the tin atom in each complex is five-coordinate with a highly distorted geometry intermediate of square pyramidal and trigonal bipyramidal. Again Sn⋯O contacts are weak and do not qualify as coordinate bonds.

Synthesis of aromatic tetracyclic tin compounds by template and transmetallation reactions: Alkyl vs aryl migration from tin to nitrogen

The syntheses of [bis(3,5-di- tert-butyl-2-hydroxy-2-phenyl)amine]diphenyltin ( 1) and [bis(3,5-di- tert-butyl-2-hydroxy-2-phenyl)amine]dichloro-phenyl-stannate ( 2) by template reactions using 3,5-di- tert-butylcatechol, aqueous ammonia and SnPh 2Cl 2 are reported. We also report the syntheses of compounds 2, [bis(3,5-di- tert-butyl-2-hydroxy-2-phenyl)amine]trichloro-stannate ( 4), [bis(3,5-di- tert-butyl-2-hydroxy-2-phenyl)methylamine]chloro-methyltin ( 5), and [bis(3,5-di- tert-butyl-2-hydroxy-2-phenyl)- n-butylamine] n-butyl-chlorotin ( 6) and [bis(3,5-di- tert-butyl-2-hydroxy-2-phenyl)amine] n-butyl-dichloro-stannate ( 7), performed by transmetallation reactions of the octahedral zinc coordination compound Zn[3,5-di- tert-butyl-1,2-quinone-(3,5-di- tert-butyl-2-hydroxy-1-phenyl)imine] 2 ( 3) with SnPhCl 3 or SnPh 2Cl 2, SnCl 4, SnMe 2Cl 2, Sn( nBu) 2Cl 2 and Sn( nBu)Cl 3, respectively. The X-ray diffraction structures of compounds 1, 2, 4 and 6 are reported. The transmetallation reactions with Sn(alkyl) 2Cl 2 afforded pentacoordinated tin compounds, where an alkyl group migrated from tin to nitrogen, while similar reactions with Sn–Ph compounds did not present any phenyl group migration.

Coordination polymers containing ferrocene backbone. Synthesis, structure and electrochemistry

The reaction of 1,1'-ferrocenedicarboxylic acid (LH(2)) with bis(triphenyltin) oxide afforded a molecular heterobimetallic compound [(Ph(3)Sn)(2)L]. In the latter the two carboxylate units of [L](2-) are involved in an anisobidentate chelating coordination mode to two triphenyl tin units. The reaction of LH(2) with trimethyltin hydroxide or bis(tri-n-butyltin) oxide afforded 2D-coordination polymers [(Me(3)Sn)(2)L](n) and [(n-Bu(3)Sn)(2)L](n) which are formed as a result of anisobidentate bridging coordination action of the two carboxylate units of [L](2-). Interestingly the 2D-coordination polymers contain 24-membered macrocycles each of which is comprised of four trialkyl tin units. The coordination unsaturation of [(Ph(3)Sn)(2)L] can be utilized to form coordination polymers. Accordingly the reaction of LH(2) with bis(triphenyltin) oxide in the presence of ditopic nitrogen ligands such as 4,4'-bipyridine, 4,4'-trimethylenebipyridine or 4,4'-vinylenebipyridine afforded one-dimensional coordination polymers which contain in their backbone three distinct structural components viz., two triorganotin units, a ferrocenyl unit and a bridging nitrogen ligand unit. The coordination polymers, however, do not retain their structural integrity in solution and fall apart to their monomeric units. Electrochemical studies on these hybrid orgaonotin/ferrocene systems reveal that most of them exhibit a single quasi-reversible oxidation peak.

Synthesis and thermolytic behavior of tin(iv) formates: in search of recyclable metal–hydride systems

The synthesis and characterization of the series of organotin formates together with their thermolytic behavior are described. The diformate Bu(n)(2)Sn{OC(O)H}(2) (1) was synthesized by the reaction of Bu(n)(2)SnH(2) with formic acid. The triorganotin monoformate compounds R(3)SnOC(O)H (R = Cy (cyclohexyl)) 3, Mes, (mesityl, 2,4,6-trimethylphenyl) 4, and Dmp (2,6-dimethylphenyl 5) were obtained by the reaction of R(3)SnOH with formic acid. Their X-ray crystal structures along with that of the previously reported formate (PhCH(2))(3)SnOC(O)H (2) were determined. The diformate 1 exhibits an extended two-dimensional polymeric structure in which six-coordinate tin centers are linked by formate bridges. The tribenzyltin formate (2) possesses a chain structure in which the five-coordinate Sn(CH(2)Ph)(3) units are bridged by formate ions. The cyclohexyl derivative 3 was observed to have a similar structure. In contrast, the Mes and Dmp derivatives 4 and 5 support monomeric structures in which the four-coordinate tin atom is bound to an oxygen of the formate ligand. Heating the compounds in various high boiling solvents produced no decomposition up to 120 °C in the case of 1 and refluxing a solution of 2 or 3 in mesitylene or diglyme left the starting material mostly unchanged, although 3 decomposed to an insoluble orange solid in refluxing decalin. In contrast, the heating of 4 and 5 in refluxing mesitylene led to elimination of CO to give the tin hydroxides. The results are in contrast to the known thermolytic behavior of R(3)SnOC(O)H (R = Pr(n) or Bu(n)) complexes, which eliminate CO(2) to generate R(3)SnH. Compounds 3-5 are rare examples of structurally characterized tin formates.

Monoorganooxotin cage, diorganotin ladders, diorganotin double chain and triorganotin single chain formed with phosphonate and arsonate ligands

The solvothermal reaction of n-BuSn(O)OH with PhPO(3)H(2) afforded the hexanuclear monoorganooxotin phosphonate cage, {[(n-BuSn)(3)(MeO)(3)O](2)(O(3)PPh)(4)}.MeOH 1. When the n-Bu(2)Sn(PhCO(2))(2) precursor reacted with PhPO(3)H(2) in a 1 : 1 stoichiometric ratio, the diorganotin phosphonate ladder [n-Bu(2)SnO(3)PPh](n) 2 was obtained. The reaction of [n-Bu(2)(PrO)Sn](2)O with 4-OH-3-NO(2)-C(6)H(3)AsO(3)H(2) affords the diorganotin arsonate ladder [n-Bu(2)Sn(4-OH-3-NO(2)-C(6)H(3)AsO(3))](n) 3, while the reaction of [n-Bu(2)(PrO)Sn](2)O with 4-NO(2)-C(6)H(4)AsO(3)H(2) and 4-Me-C(6)H(4)SO(3)H gives an diorganotin double chain [n-Bu(2)Sn(4-Me-C(6)H(4)SO(3))(4-NO(2)-C(6)H(4)AsO(3)H)](n) 4, which contains both sulfonate and arsonate ligands. The reaction of 4-NO(2)-C(6)H(4)AsO(3)H(2), EtONa, and Ph(3)SnCl yields a new triorganotin arsonate single chain [(Ph(3)Sn)(4)(4-NO(2)-C(6)H(4)AsO(3))(2).H(2)O](n) 5. The NMR ((1)H, (13)C, (119)Sn) spectra of compounds 1 and 4 were studied.

In search for a pentacoordinated monoorgano stannyl cation

Abstract Alkylation of Sn(OCH2CH2NMe2)2 (1) by MeI or MeOTf leads to a mixture of quaternary ammonium salts by alkylation of the NMe2 moiety. Reaction of Sn(acac)2 (2) with MeOTf gives unexpected redistribution product Sn(acac)OTf (3), which is a rare example of mono acetylacetonato tin (II) derivatives. Pentacoordinated monoorgano stannyl cation PhSn ( OCH 2 CH 2 NMe 2 ) 2 + was generated by salt metathesis from PhSn(OCH2CH2NMe2)2Cl (5) and Ag[Al(OCH(CF3)2)4] or Ag[B(C6F5)4]. This cation was not isolated due to its strong electrophilic nature. It abstracts substituents from aluminate and borate weakly coordinating anions (WCAs) leading to redistribution products [Al[OCH(CF3)2]2OCH2CH2NMe2]2 (6) and [Ph(C6F5)Sn(OCH2CH2NMe2)2][H2OB(C6F5)3] (9), respectively. Structures of 3 and 6 were established by single-crystal X-ray diffraction analysis.

Organotin meclofenamic complexes: Synthesis, crystal structures and antiproliferative activity of the first complexes of meclofenamic acid – Novel anti-tuberculosis agents

The complexes [Me(2)(Meclo)SnOSn(Meclo)Me(2)](2) (2) and [Ph(3)Sn(Meclo)] (3) where HMeclo is meclofenamic acid, N-(2,6-dichloro-m-tolylanthranilic acid)], have been prepared and structurally characterized by means of vibrational, (1)H and (13)C NMR spectroscopies. The crystal structure of complexes (2) and (3) have been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement of (2). The structure is centro symmetric and features a central rhombus Sn(2)O(2) unit two additional tin atoms linked at the oxygen atoms. Five- and six-coordinated tin centers are present in the dimer distannoxane. X-ray analysis of (3) revealed a penta-coordinated structure containing Ph(3)Sn coordinated to the chelated carboxylato group. The polar imino hydrogen atom participates in intra-molecular hydrogen bonds. Complexes (2) and (3) are self-assembled via pi-->pi, C-H-pi, stacking interactions and intra-molecular hydrogen bonds. Meclofenamic acid and [Ph(3)Sn(Meclo)] have been evaluated for antiproliferative activity in vitro against three human cancer cell lines: MCF-7 (human breast cancer cell line), T24 (bladder cancer cell line), A-549 (non-small cell lung carcinoma) and a mouse L-929 (a fibroblast-like cell line cloned from strain L). The [Ph(3)Sn(Meclo)] complex exhibited high cytotoxic activity against all the cancer cell lines. Meclofenamic and [Ph(3)Sn(Meclo)] were tested for anti-mycobacterial activity against Mycobacterium tuberculosis H37Rv. The [Ph(3)Sn(Meclo)] complex was found to be a promising anti-mycobacterial lead compound, displaying high activity against M. tuberculosis H37Rv.

Oxidation by Oxygen and Sulfur of Tin(IV) Derivatives Containing a Redox‐Active o‐Amidophenolate Ligand

Oxidation of tin(IV) o-amidophenolate complexes [Sn(ap)Ph(2)] (1) and [Sn(ap)Et(2)(thf)] (2) (ap=dianion of 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone (ImQ)) with molecular oxygen and sulfur in toluene solutions was investigated. The reaction of oxygen with 1 at room temperature forms a paramagnetic derivative [Sn(isq)(2)Ph(2)] (3) (isq=radical anion of ImQ) and diphenyltin(IV) oxide [{Ph(2)SnO}(n)]. Interaction of 1 with sulfur gives another monophenyl-substituted paramagnetic tin(IV) complex, [Sn(ap)(isq)Ph] (4), and the sulfide, [Ph(3)Sn](2)S. The oxidation of 2 with oxygen and with sulfur proceeds through the derivative [Sn(isq)(2)Et(2)] (7), which undergoes alkyl elimination to give two new tin(IV) compounds, [Sn(ap)(isq)Et] (5) and [Sn(ap)(EtImQ)Et] (6) (EtImQ=2,4-di-tert-butyl-6-(2,6-diisopropylphenylimino)-3-ethylcyclohexa-1,4-dienolate ligand), respectively, along with the corresponding alkyltin(IV) oxide and sulfide. Complexes 3-5 and 7 were studied by EPR spectroscopy. The structures of 3, 4 and 6 were investigated by X-ray analysis.

Synthesis, characterization and biological activities of some new organotin(IV) derivatives: Crystal structure of [(Sn Ph 3) (OOCC 6H 4OH)] and [(SnMe 3) 2 (OOC) 2C 6Cl 4 (DMSO) 2

Some new organotin(IV) carboxylates 1– 3 of 2-hydroxybenzoic acid (L A) and 4– 6 of 2,3,4,5-tetrachloro-6-(methoxycarbonyl) benzoic acid (L B) have been synthesized, respectively, by the esterification of triorganotin oxide/hydroxide with the corresponding acids in an appropriate mole ratios. Multinuclear NMR ( 1H, 13C and 119Sn), IR and X-ray crystallographic studies were carried out to elucidate their structures both in solution and in solid state. The X-ray crystallographic data for 3 was recollected at low temperature. The compound 4 was dissolved in DMSO and a new compound 4 · 2DMSO [(SnMe 3) 2(OOC) 2C 6Cl 4(DMSO) 2] was crystallized out. The structure shows that two Sn moieties are attached to the ligand (L B) through two carboxylic groups. The two molecules of DMSO are coordinated to each of the Sn atoms via oxygen atom to terminate the conventional polymeric chain of trimethyl carboxylates to a discrete molecule, having trigonal bipyramidal geometry around the Sn atoms. Some of the synthesized compounds exhibited significant antifungal activities and have a potential to be used as drugs.

Re-visiting of 5-[( E)-2-(aryl)-1-diazenyl]-quinolin-8-ol with tweaking of Sn–Ph groups: Synthesis, spectroscopic characterization and X-ray crystallography

Reactions of sodium 5-[( E)-2-(aryl)-1-diazenyl]quinolin-8-olates (LH, where the aryl group is an R-substituted phenyl ring such that for L 1H: R = H; L 2H: R = 2′-CH 3; L 3H: R = 3′-CH 3; L 4H: R = 4′-CH 3; L 5H: R = 4′-OCH 3 and L 6H: R = 4′-OC 2H 5) with Ph 3SnCl in a 1:1 molar ratio yielded complexes of composition Ph 3SnL. The complexes have been characterized by 1H, 13C, 119Sn NMR, IR and 119mSn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of Ph 3SnL 1 · 0.5C 6H 6 ( 1), Ph 3SnL 2 ( 2), Ph 3SnL 5 · C 6H 6 ( 5) and Ph 3SnL 6 · 0.5C 6H 6 ( 6) were determined. The results of the X-ray studies indicated that the benzene solvated compounds 1, 5 and 6 are distorted square pyramid, with one of the phenyl C atoms in the apex while the ligand arrangement around central Sn atom in 2 is distorted trigonal-bipyramidal, with a phenyl C and the oxinato N atoms in axial positions.

Ruthenium and osmium carbonyl clusters incorporating stannylene and stannyl ligands

The reaction of [Ru(3)(CO)(12)] with Ph(3)SnSPh in refluxing benzene furnished the bimetallic Ru-Sn compound [Ru(3)(CO)(8)(mu-SPh)(2)(mu(3)-SnPh(2))(SnPh(3))(2)] which consists of a SnPh(2) stannylene bonded to three Ru atoms to give a planar tetra-metal core, with two peripheral SnPh(3) ligands. The stannylene ligand forms a very short bond to one Ru atom [Sn-Ru 2.538(1) A] and very long bonds to the other two [Sn-Ru 3.074(1) A]. The germanium compound [Ru(3)(CO)(8)(mu-SPh)(2)(mu(3)-GePh(2))(GePh(3))(2)] was obtained from the reaction of [Ru(3)(CO)(12)] with Ph(3)GeSPh and has a similar structure to that of as evidenced by spectroscopic data. Treatment of [Os(3)(CO)(10)(MeCN)(2)] with Ph(3)SnSPh in refluxing benzene yielded the bimetallic Os-Sn compound [Os(3)(CO)(9)(mu-SPh)(mu(3)-SnPh(2))(MeCN)(eta(1)-C(6)H(5))] . Cluster has a superficially similar planar metal core, but with a different bonding mode with respect to that of . The Ph(2)Sn group is bonded most closely to Os(2) and Os(3) [2.786 and 2.748 A respectively] with a significantly longer bond to Os(1), 2.998 A indicating a weak back-donation to the Sn. The reaction of the bridging dppm compound [Ru(3)(CO)(10)(mu-dppm)] with Ph(3)SnSPh afforded [Ru(3)(CO)(6)(mu-dppm)(mu(3)-S)(mu(3)-SPh)(SnPh(3))] . Compound contains an open triangle of Ru atoms simultaneously capped by a sulfido and a PhS ligand on opposite sides of the cluster with a dppm ligand bridging one of the Ru-Ru edges and a Ph(3)Sn group occupying an axial position on the Ru atom not bridged by the dppm ligand.