Metallkomplexe von Farbstoffen — Übergangsmetall‐Komplexe mit 2‐(1,3‐Dioxo‐2‐indanyliden)benzimidazolinen

Metal Complexes of Dyes — Transition Metal Complexes of Mono‐ and Dianions of 2‐(1,3‐Dioxo‐2‐indanylidene)‐benzimidazolines 2‐(1,3‐Dioxo‐2‐indanylidene)benzimidazolines (L) ( 1 — 6 ) react with metal salts and chloro‐bridged complexes in the presence of NaH to give the mono and bis‐ N , O ‐chelate complexes (L — H + ) 2 M (M=Cu, Pd, Ni) ( 7 — 9 ), (L — H + )M(PR 3 )Cl (M=Pd, Pt; 10 — 15 and (L — 2H + )[Pt(PEt 3 )Cl] 2 ( 16 , 17 ). The electronic spectra of the bis(chelate) complexes show a large bathochromic shift of the absorptions in the visible region as compared to the free ligands. The structures of (L — H + )Pd(Cl)‐(P n B u 3 ) ( 10 ) and of (L — 2H + )[Pt(Cl)PEt 3 )] 2 ( 16 ) have been determined by X‐ray crystallography. The two heterocyclic planes in 16 are bent along the elongated central CC bond [143.2(12)pm] which gives a hip‐roof‐like structure.