Verfahren zur Sensibilisierung photographischer Emulsionen und zugehoerige sensibilisierte Emulsion

Compounds having the general formula: wherein R and R1 are alkylene groups the carbon chain of which may be interrupted by an oxygen or sulphur atom or by a carboxylic ester, carbonic ester or carboxylic amide linkage, and Q is oxygen or sulphur, the compounds containing at least 12 atoms in the ring at least one of which is an oxygen or nitrogen atom, and the general formula: wherein R1 and R11 are alkylene groups and m and n are 1 to 3, the compounds containing at least 12 atoms in the ring, are prepared by heating together an alkali metal sulphide with a compound halogen-R-halogen or by reacting the latter compound with a compound HS-R1-SH. Compounds having the general formula: wherein R2 is an alkylene group and X and Y are alkylene groups the carbon chain of which may be interrupted by an oxygen or sulphur atom, or X may be Z-CH= where Z represents a phenyl group which may carry a sulpho, carboxy, hydroxy or amino substituent, the compounds containing at least 12 atoms in the ring, are prepared by one of the following reactions: (1) By reacting a bis-mercaptan HS-Y-SH with an N;N1- methylane bis-acrylamide (CH2=CH.CO NH)2X; (ii) by reacting a bis-mercaptan HS-Y-SH with a bis-halomethylene amide, e.g. (Br(CH2)n.CONH)2X; (iii) by reacting a bis-halide e.g. Cl-Y-Cl with a bis-mercaptomethylene amide (HSCH2CH2. CONH)2X; (iv) by reacting a bis-mercaptan HS-Y-SH with acrylamide and then with an aldehyde or ketone; (v) by reacting a dicarboxylic acid or a halide or anhydride thereof, with an aliphatic diamine. Compounds having the general formula: wherein R3 is an alkylene group and R2 is as defined above, are prepared by reacting a halogensubstituted carbonic acid ester with sodium sulphide. Specifications 235,211, 541,589, 545,448, 627,814, 636,140, 649,660, 660,012, 680,485, 711,488, 736,922, 739,912, 791,219, 800,108, 873,198, 886,722, 904,462 and U.S.A. Specification 2,948,614 are referred to.