Richard Attila Varga

An aldol condensation reaction between [2-(O=CH)C₆H₄]SnPh₂Cl and acetone gave [2-{CH₃C(=O)CH₂(OH)CH}C₆H₄]SnPh₂Cl (1). The compound was characterized in a solution using multinuclear NMR spectroscopy and HR-MS spectrometry and in a solid state using IR spectroscopy and single-crystal X-ray diffraction. The molecular structure revealed the presence of both enantiomers in the crystal.

A series of C,O ‐chelated organotin(IV) alkoxides, L ₂ PhSnO ^t Bu ( 4 ), L ₂ PhSnOMe ( 6 ), L ₂ Sn(O ^t Bu) ₂ ( 11 ), and siloxides L ₂ PhSnOSiPh ₃ ( 3 ), L ₂ Sn(OSiPh ₃ ) ₂ ( 10 ) (L=[2‐(CH ₂ O) ₂ CH]C ₆ H ₄ ), was prepared by salt elimination reactions. They were obtained from the organotin(IV) iodides L ₂ PhSnI ( 1 ) or L ₂ SnI ₂ ( 2 ) upon reactions with ^t BuOK, MeONa or Ph ₃ SiONa, respectively, in dry THF or methanol. Under non‐inert conditions, compounds 4 and 6 undergo combined hydrolysis and condensation to give the hexaorganodistannoxane (L ₂ PhSn) ₂ O ( 5 ). The stannoxane 5 is easily hydrolysed to L ₂ PhSnOH ( 7 ), which quickly converts back when heated. Basic hydrolysis of diiodide 2 produces the cyclic oxide (L ₂ SnO) ₃ ( 8 ). Its reaction with an equimolar amount of Ph ₃ SiONa gives only a mixture of the expected L ₂ SnI(OSiPh ₃ ) ( 9 ), 10 and the precursor, 2 . Yet, 8 shows a unique reactivity pattern when combine with m ‐tolyl boronic acid, affording stannaboroxane (L ₂ SnO) ₂ OB( m ‐tol) ( 12 ). All the isolated species were characterised in solution by NMR spectroscopy and mass spectrometry. The solid‐state molecular structures of 1 – 5 , 10 – 12 were established by single‐crystal X‐ray diffraction (XRD). Additionally, thermogravimetric analysis of 3 – 5 , 8 , 10 , and 12 was conducted.

Novel plumbylenes or diplumbanes bearing C,O-chelating ligands could be obtained depending on the bulkiness of the substituents on the pendant arm.

Organotin(IV) chemistry is nowadays in a continuous expansion due to the biological and medicinal potential found for some of these species. Within this study, the cytotoxic activity of several organotin(IV) compounds was investigated on two lung cancer cell lines (H522 and SK‐MES‐1) and on a normal lung cell line in order to have an overview of the toxicity and the selectivity of these derivatives. Moreover, the synthetic protocols, as well as the structural particularities of the novel organotin(IV) species, are also discussed. Hydrolysis of [2‐{(CH₂O)₂CR}C₆H₄]₂SnPh₂[R = H (1), Me (2)] withp‐toluenesulfonic acid as a proton source afford the expected derivatives [2‐(O═CR)C₆H₄]₂SnPh₂[R = H (3), Me (4)]. When hydrochloric acid is used in these reactions, a chlorine‐phenyl exchange took place in addition to the removal of the acetal fragments and the following products [2‐(O═CR)C₆H₄]₂SnPhCl [R = H (5), Me (6)] were isolated. Treatment of5with 2 equiv of 3‐aminomethylpyridine in neat affords the imino(aryl)tin compound 2‐(3′‐PyCH₂N═CH)C₆H₄]₂SnPhCl (7). The reaction between6and potassium nicotinate allows the isolation of the organotin(IV) carboxylate [2‐{O═C (CH₃)}C₆H₄]₂SnPh[O(O)CC₅H₄N‐3] (8). Compounds1–8were characterized by multinuclear NMR spectroscopy in solution, mass spectrometry, and IR spectroscopy, and their molecular structures were confirmed by X‐ray diffraction analysis. Compounds1–8were investigated for their antitumoral effects onHomo sapienslung cancer cell lines (H522 and SK‐MES‐1) and on a normal bronchial epithelial cell line, BEAS‐2B.

Hydrolysis of [2-{(CH₂O)₂CH}C₆H₄]SnPh₃ (1) results in the isolation of [2-(OCH)C₆H₄]SnPh₃ (2) in a very good yield. Reduction of 2 with NaBH₄ gives an almost quantitative yield of [2-(HOCH₂)C₆H₄]SnPh₃ (3), when 2 is treated with appropriate amines in the absence of any solvent, [2-(4′-PyCH₂NCH)C₆H₄]SnPh₃ (4) and [2-{3′,5′-(MeOOC)₂–C₆H₃NCH}C₆H₄]SnPh₃ (5) are isolated in high yields. Adding NaBH₄ to a THF solution of 4 leads to [2-(4′-PyCH₂NH–CH₂)C₆H₄]SnPh₃·BH₃ (6), the first aryltin(IV) compound with a ligand containing a secondary amine functional group coordinated to the metal centre. The reaction of 4 with [PdCl₂(NCMe)₂] and [Cu(hfac)₂·(H₂O)] (hfac = hexafluoroacetylacetonate) in a 2 : 1 molar ratio gave the corresponding heterometallic complexes [{2-(4′-PyCH₂NCH₂)C₆H₄SnPh₃}₂PdCl₂] (7) and [{2-(4′-PyCH₂NCH₂)C₆H₄SnPh₃}₂Cu(hfac)₂] (8), respectively. The purity of the compounds was confirmed by elemental analysis and high-resolution mass spectrometry. Multinuclear NMR spectroscopy was used to investigate the solution behaviour of these compounds and the molecular structures for 1, 2, and 4–8 were established by single-crystal X-ray diffraction.

In recent decades, organotin(IV) chemistry has seen a rapid growth owing to the biological, pharmaceutical and medicinal applications found for different compounds. The aim of this study was the evaluation of the antiproliferative activity of several organotin(IV) compounds for a better understanding of the structure–activity relationship (SAR). The synthesis and structural features of the new organotin(IV) species are also presented. Thus, the treatment of [2-{(CH₂O)₂CH}C₆H₄]Me₂SnCl (1) and [2-(OCH)C₆H₄]Me₂SnCl (2) with potassium salts of isonicotinic and nicotinic acids resulted in the isolation of [2-{(CH₂O)₂CH}C₆H₄]Me₂Sn[O(O)CC₅H₄N-4] (3), [2-{(CH₂O)₂CH}C₆H₄]Me₂Sn[O(O)CC₅H₄N-3] (4), [2-(OCH)C₆H₄]Me₂Sn[O(O)CC₅H₄N-4] (5) and [2-(OCH)C₆H₄]Me₂Sn[O(O)CC₅H₄N-3] (6), respectively, in high yields. The one pot reaction between compound 2, isonicotinic acid and sodium hydroxide allows the formation of [2-(EtOOC)C₆H₄]Me₂Sn[O(O)(CC₅H₄N-4)] (7) in a moderate yield. The novel compounds were characterized by multinuclear NMR spectroscopy, mass spectrometry and IR spectroscopy. The molecular structures of compounds 3–5 and 7 were established via single crystal X-ray diffraction; in all cases a distorted trigonal bipyramidal coordination geometry was found around the metal center, as a result of the strong intramolecular O→Sn coordination. Compounds 1–6 were investigated for their in vitro antiproliferative activity towards the mouse colon carcinoma C26 cell line with the preliminary results showing a better activity than that of 5-fluorouracil.

A new lanthanum and manganese ethylenediaminetetraacetate (EDTA) coordination polymer (EDTA⁴⁻ = [(CH₂N)₂(CH₂-COOH)(CH₂COO)₄]) was synthesized from La(NO₃)₃ and Mn(NO₃)₂ reagents, ethylenediaminetetraacetic acid, and water at room temperature. The structure of the new compound formed, [{La₂Mn₃(EDTA)₃(H₂O)₁₁}·12H₂O]_n, was determined by the single crystal X-ray diffraction technique. The synthesis and characterization of the La(III) and Mn(II) coordination complex, characterized by FTIR spectroscopy, thermogravimetry, and differential thermal analysis of the complex, are envisaged. X-ray crystal structure determination indicates that seven- and four-coordinate modes between La(III)/Mn(Π) and H₄EDTA exist. [{La₂Mn₃(EDTA)₃(H₂O)₁₁}·12H₂O]_n crystallizes in the monoclinic space group C2 with unit cell parameters of a = 16.1227(17) Å, b = 14.8049(16) Å, c = 14.8736(16) Å, and β = 116.107(2)°. Using this precursor, LaMnO₃ (LMO) epitaxial thin films were grown by the polymer-assisted deposition (PAD) method on (100)SrTiO₃ (STO) single crystalline substrates at a temperature of 900 °C. The LMO crystallized films exhibit a (001)LMO/(001)STO out-of-plane epitaxial relationship and a smooth surface morphology.

1,2-Bis(3-methyl-4-imidazolin-2-selone)ethane was used to stabilize the first example of an authentic mesityltellurenyl cation, [MesTe] ⁺ , as a charge transfer adduct featuring a 3c-4e Se→Te←Se three-body system.

Organotin( iv ) compounds might be used as linkers for building coordination polymers as suggested by the isolation of [{2-(OCH)C ₆ H ₄ }Me ₂ SnO(O)CC ₅ H ₄ N-4]ZnTPP.