Silver halide photographic materials

Abstract

The present invention provides silver halide photographic materials containing a havel compound, which when reduced, releases a photographically useful group as triggered off by the cleavage of the nitrogen-oxygen single bond in the compound and which is represented by the following general formula (I): ##STR1## wherein EAG represents a group which accepts an electron from a reducing substance; N and O each represents nitrogen atom and an oxygen atom, respectively; R.sup.1 and R.sup.2 each represents a substituent other than a hydrogen atom, and when R.sup.1 or R.sup.2 is bonded to --(Time).sub.t PUG, R.sup.1 or R.sup.2 is a mere bond or a substituent other than a hydrogen atom, and R.sup.1 and R.sup.2 may be bonded to each other to form a ring; Time represents a group for releasing PUG via the subsequent reaction as triggered off by the cleavage of the nitrogen-oxygen single bond in the compound of general formula (I); PUG represents a photographically useful group; t is an integer of 0 or 1; the full lines in the formula each means a bond; and the dotted lines therein mean that at least one of the dotted lines is a bond. In particular, compounds of the following formula (II) and (III) are preferred among those of the formula (I): ##STR2## wherein R.sup.3 is bonded to the nitrogen atom or oxygen atom in the formula, and represents an atomic group necessary for the formation of a 3 to 8-membered mono- or fused-hetero ring; ##STR3## wherein R.sup.4 and R.sup.5 each represents a mere bond, a hydrogen atom or a substituent group, and they may be bonded to each other to form a saturated or unsaturated carbon ring or hetero ring; and X represents a divalent binding group.

Dependencies are inferred from the claim text.