Complex formation with chelating ligands like 5-phenylazo-8-quinolinol, 5-(21-carboxyphenylazo)-8-quinolinol, 1,2-dihydroxyanthraquinone (i.e., alizarin), and 1-nitroso-2-naphthol is due to nucleophilic attack on tin of the P-alkoxycarbonylalkyltin chlorides (a unique class of PVC stabilizer intermediates) with the subsequent elimination of h drogen chloride. A number of complexes of the types R2SnL2. RSnL2Cl, R2SnLCl, R2Sn(~'H')2, R2SnL1', and RSnLY'Cl (where R = CH30COCH2CH2-, C4H90COCH2CH2-, and CH30COCH(CH3)CH2-; LH = 5-phenylazo-8-quinolinol, l-nitroso-2-naphthol; L'HH' = 5-(21-carboxyphenylazo)-8-quinolinol; and LnH2 = 1,2-dihydroxyanthraquinone) and a thiocyanate derivative viz. (CH30COCH2CH2)2Sn(SCN)2 have been prepared. 5-Arylazo-8-quinolinols exhibit azo-hydrazone tautomeric equilibria but their complexes exist only in the azo form. P-Alkoxycarbonylethyltin alizarinates are somewhat different from other complexes. In these complexes two hydroxyl groups of alizarin have been utilised in complex formation, moreover, one of the two carbonyl groups of alizarin also remains involved in coordination to tin. In (CH30COCH2CH2)2Sn(SCN)2, the thiocyanate group is possibly linked to tin atom through nitrogen. All the complexes and the thiocyanate derivative have been characterised by elemental analyses, electronic, ir, and 'H nmr spectra. Possible structural features of the compounds are discussed.

Dithizone forms stable complexes with β‐alkoxycarbonyl ethyl tin chlorides (the so called “Estertins” – a unique class of PVC stabilizer). Reduction of Lewis acidity of the resulting organotin chloride can improve the efficiency of a stabilizer and therefore the β‐alkoxycarbonyl ethyl tin dithizonates are likely to show PVC stabilization property. A number of β‐alkoxycarbonyl ethyl tin dithizonates of the types R2SnL2, R2SnLX, and RSnL2X where R = CH3OCOCH2CH2–, C4H9OCOCH2CH2–, and CH3OCOCH(CH3)CH2–; X = Cl, SCN and L = Dithizone (i. e. 1,5‐diphenyl thiocarbazone) and one complex (CH3OCOCH2CH2)2SnL′Cl where L′ = Diphenylcarbazone have been prepared and characterized by elemental analysis, electronic, IR and PMR spectral data. Possible structural features of the isolated complexes have also been discussed. Preliminary evaluation of the complex (CH3OCOCH2CH2)2Sn(HDz)2 as a PVC stabilizer has also been reported.

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232ChemInform Abstract Dithizone (II) forms stable complexes with the compounds (I) and (IV), the so-called "Estertins" -a unique class of PVC stabilizers. Reduction of Lewis acidity of the resulting organotin chloride can improve the efficiency of a stabilizer and therefore the complexes prepared are likely to have PVC stabilizing properties. The method of synthesis is shown in the scheme. (VIb) is obtained by metathesis of (VIa) with KSCN in EtOH. (VII) is prepared analogously to the dithizonates. With the exception of (VI) which is believed to have a trigonal-bipyramidal arrangement around the metal, all the compounds have a distorted octahedral geometry in which the term cis-and trans-configuration is of little significance. Two different modes of hydrogen bridging are possible for (III), (V) and (VI). Thestructure of (VII) cannot be assigned unambiguously. (IIIa) is used to perform preliminary mill heat stability and oven heat stability tests as a PVC stabilizer.