The present invention relates to the compounds of formula I ##STR1## and metal complexes thereof, in which both R.sub.1 's are hydrogen or halogen or form a condensed ring of the benzene series, or --S--CH.sub.2 CH.sub.2 --S--, and R.sub.3 is hydrogen, a mono- or dicyclic-aromatic group or is a divalent radical of the phenylene or naphthalene series linking one further compound of formula I, wherein R.sub.3 is a direct bond and the R.sub.1 groups are the same as or different from the R.sub.1 groups of the first compound of formula I, which metal complexes are either 1:1 metal complexes when R.sub.3 is a divalent linking radical, or 1:2 metal complexes of monomeric compounds of formula I such 1:2 complexes being symmetric or asymmetric and the metal is a divalent transition metal, the complexes are useful as pigments.
本发明涉及公式I的化合物及其
金属配合物,其中两个R1'均为氢或卤素,或形成苯系的紧缩环,或为--S--CH2CH2--S--,而R3为氢、单环或双环芳基,或是苯环或
萘环系的双价基团,连接另一个公式I的化合物,其中R3为直接键,且R1基团与公式I的第一个化合物中的R1基团相同或不同。这些
金属配合物为1:1
金属配合物,当R3为双价连接基团时,或为公式I单体化合物的1:2
金属配合物,这些1:2配合物是对称或非对称的,而
金属为双价过渡
金属。这些配合物可用作
颜料。