Patent ID: 7303863

Claim:
A silver halide emulsion, which is chemically sensitized by a compound represented by formula (I): wherein, in formula (1), Ch represents a sulfur atom, a selenium atom, or a tellurium atom; X 1 represents NR 1 , or N + (R 2 )R 3 Y − , in which R 1 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R 2 and R 3 each independently represent an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and Y − represents an anionic ion; X 2 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, OR 4 , or N(R 5 )R 6 , in which R 4 , R 5 , and R 6 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; and E is a group selected from groups represented by formula (2), (3), (4), or (5): wherein, in formula (2), Z represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, OR 7 , or N(R 8 )R 9 , in which R 7 , R 8 , and R 9 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; wherein, in formula (3), A 1 represents an oxygen atom, a sulfur atom, or NR 13 ; and R 10 , R 11 , R 12 , and R 13 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; wherein, in formula (4), A 2 represents an oxygen atom, a sulfur atom, or NR 17 ; R 14 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, or an acyl group; R 15 , R 16 , and R 17 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; W represents a substituent; n is an integer from 0 to 4; when n is 2 or more, Ws may be the same or different; and wherein, in formula (5), L represents a divalent linking group; and EWG represents an electron withdrawing group.