Light-sensitive silver halide grain
View Patent ↗A light-sensitive silver halide grain having an absorption band in a wavelength region of visible light is prepared to provide a silver halide photographic material having high spectral sensitivity in the visible region. The silver halide photographic material contains the light-sensitive silver halide grain having a metal complex dopant having an absorption band which has a molar absorption coefficient of 10,000 or more in a wavelength region of visible light in an ultraviolet-visible absorption spectrum of a solution thereof.
1. A light-sensitive silver halide grain comprising a metal complex dopant having an absorption band which has a molar absorption coefficient of 10,000 or more in a wavelength region of visible light in an ultraviolet-visible absorption spectrum of a solution thereof,
wherein the metal complex dopant has at least one heteorcyclic compound as a ligand, and the number of inorganic anions coordinating to a central metal in the metal complex dopant does not exceed the majority of the coordination number of the complex.
2. The light-sensitive silver halide grain as claimed in claim 1 , wherein the metal complex dopant contained in the silver halide grain has an absorption band having a molar absorption coefficient of 10,000 or more between wavelengths of 380 nm and 780 nm.
3. The light-sensitive silver halide grain as claimed in claim 1 , wherein the majority of coordination sites of the central metal of the metal complex dopant contained in the silver halide grain are occupied by heterocyclic compounds.
4. The light-sensitive silver halide grain as claimed in claim 1 , wherein the central metal of the metal complex dopant contained in the silver halide grain is a metal or a metal ion selected from the group consisting of iron, cobalt, nickel, copper and ruthenium.
5. A silver halide emulsion comprising a silver halide grain, wherein the silver halide grain comprises a metal complex dopant having an absorption band which has a molar absorption coefficient of 10,000 or more in a wavelength region of visible light in an ultraviolet-visible absorption spectrum,
wherein the metal complex dopant has at least one heterocyclic compound as a ligand, and the number of inorganic anions coordinating to a central metal in the metal complex dopant does not exceed the majority of the coordination number of the complex.
6. A silver halide photographic material comprising a support having thereon at least one silver halide emulsion layer, wherein a silver halide grain contained in the emulsion comprises a metal complex dopant having an absorption band which has a molar absorption coefficient of 10,000 or more in a wavelength region of visible light in an ultraviolet-visible absorption spectrum of a solution thereof,
wherein the metal complex dopant has at least one heterocyclic compound as a ligand, and the number of inorganic anions coordinating to a central metal in the metal complex dopant does not exceed the majority of the coordination number of the complex.