摘要:
A photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula: ##STR1## wherein A is a silver halide adsorptive group that contains at least one atom of N, S, Se, or Te that promotes adsorption to silver halide, and Z is a light absorbing group including for example cyanine dyes, complex cyanine dyes, merocyanine dyes, complex merocyanine dyes, homopolar cyanine dyes, styryl dyes, oxonol dyes, hemioxonol dyes, and hemicyanine dyes, and XY is an fragmentable electron donor moiety in which X is an electron donor group and Y is a leaving group other than hydrogen, and wherein:1) XY has an oxidation potential between 0 and about 1.4 V; and2) the oxidized form of XY undergoes a bond cleavage reaction to give the radical X.sup..cndot. and the leaving fragment Y.In a preferred embodiment of the invention, the radical X.sup..cndot. has an oxidation potential .ltoreq.-0.7 V.
摘要:
This invention comprises a photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula X--H, wherein X is an electron donor moiety to which a base, B.sup.-, is covalently linked and H is a leaving hydrogen atom, and wherein:1) X--H has an oxidation potential between 0 and about 1.4 V; and2) the oxidized form of X--H undergoes deprotonation reaction with the base B.sup.-, to give the radical X.sup..cndot. and the protonated base B-H.In a preferred embodiment of the invention, the radical X.cndot. has an oxidation potential
摘要:
A photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula: ##STR1## wherein A is a silver halide adsorptive group that contains at least one atom of N, S, Se, or Te that promotes adsorption to silver halide, and L represents a linking group containing at least one C, N, S or O atom, k is 1 or 2, and XY is an fragmentable electron donor moiety in which X is an electron donor group and Y is a leaving group other than hydrogen, and wherein: 1) XY has an oxidation potential between 0 and about 1-4 V; and 2) the oxidized form of XY undergoes a bond cleavage reaction to give the radical X.sup..cndot. and the leaving fragment Y. In a preferred embodiment of the invention, the radical X.sup..cndot. has an oxidation potential .ltoreq.-0.7V.
摘要:
A process is disclosed for the preparation of 1,4-dioxy-2-butenes by reacting 3,4-epoxy-1-butene with an oxygen nucleophile in the presence of a Pd(O) complex catalyst.
摘要:
This invention provides a photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula (a): &Dgr;−(t)m−XY′ (a) XY′−(t)m−&Dgr; (b) &Dgr;−(t)m−XY′−(t)m−&Dgr; (c) wherein &Dgr; is protective group that is eliminated during development of the photographic element, t is a timing group, m is an integer from 0 to 3, and XY′ is a fragmentable electron donor moiety in which X is an electron donor group and Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is present in the emulsion or is covalently linked directly or indirectly to X, and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.4 V; 2) the oxidized form of X—Y′ undergoes a bond cleavage reaction to give the radical X• and the leaving fragment Y′, and 3) the radical X• has an oxidation potential ≦−0.7V.
摘要:
A photographic emulsion comprising dispersed in a binder sensitized silver halide grains wherein the emulsion is sensitized from an organometallic compound of formula:(R).sub.n (X).sub.m M (I)wherein M is a metal selected from the group consisting of lead, tin, boron, bismuth and thallium, each R is independently an alkyl group, a cycloalkyl group, an aryl group, a heterocyclic group, an alkenyl group or a alkynyl group, each X is independently halogen, hydroxy, or alkoxy, n is 1 to 4 and m is 0 to 3, with the proviso that when M is lead or tin, n is 1 to 4 and m+n is 4, when M is boron or bismuth, n is 1 to 3 and m+n is 3 and when M is thallium, either n is 1 and m is 0, or n is 1 to 3 and n+m is 3.
摘要:
A method of forming 4-amino-2-buten-1-ol using 3,4-epoxy-1-butene is disclosed. A nitrogen nucleophile (e.g., an amine) is reacted with 3,4-epoxy-1-butene in the presence of a polymer-bound complex of palladium having up to four phosphine ligands.