Abstract: Acenaphthylene compounds are added to dialkylzinc compositions to improve the thermal stability of the compositions.

Abstract: Novel yellow ortho, ortho' dihydroxy azomethine dyes and metal complexes of such dyes which are particularly useful in photographic products and processes are presented by this invention. The novel yellow ortho, ortho' dihydrozy azomethine dyes have the following structural formula: ##STR1## where n' is the integer 1-8 and m' is the integer 1 or 2.

Abstract: The direct reaction of metallic tin with an .alpha.,.beta.-unsaturated nitrile, hydrogen chloride, hydrogen bromide or hydrogen iodide in the presence of an alcohol yields diorgano-tin dihalides with an iminoester function in the organo groups. This iminoester function can be converted with mercaptans into the corresponding iminothioester function. The novel diorgano-tin dihalides of the formula ##STR1## wherein X represents a chlorine, bromine or iodine atom,Y represents an oxygen or sulphur atom,R represents a hydrogen atom and/or alkyl, andR' represents a hydrocarbon group of aliphatic or aromatic character which can contain functional groups,are, for example, valuable intermediates for the production of PVC stabilisers.