| abstract |
Photothermographic imaging materials having increased photospeed are provided by certain tellurium chemical sensitizers that are added during the formulation of a photothermographic emulsion. These useful chemical sensitizers are represented by the following Structure I or II: n Te(L) m (X 1 ) n I n Pd(X 2 ) 2 [Te(R′) 2 ] 2 II n wherein X 1 and X 2 independently represent halo, OCN, SCN, S(C=S)N(R a )(R b ), S(C=S)OR a , S(C=S)SR a , S(P=S)(OR a )(OR b ) 2 , S(P=S)(R a )(R b ), SeCN, TeCN, CN, SR a , OR a , N 3 , alkyl, aryl, or O(C=O)R a groups, R a and R b are an alkyl, alkenyl, cycloalkyl, heterocycyl, or aryl group, or R a and R b taken together can form a 5-, 6- or 7-membered heterocyclic ring, L is a ligand derived from a neutral Lewis base, R′ is an alkyl or aryl group, m is 0, 1, 2, or 4, and n is 2 or 4 provided that when m is 0 or 2, n is 2 or 4, and when m is 1 or 4, n is 2, and further provided that multiple X 1 , X 2 , L, R a , R b , or R′ groups in the molecule can be the same or different groups. |