Synthesis, Structures, and Properties of Diiron Azadithiolate Complexes Containing a Subphthalocyanine Moiety as Biomimetic Models for [FeFe]‐Hydrogenases

The first two model compounds for [FeFe]‐hydrogenases that contain a subphthalocyanine (SubPc) macrocycle, namely, [{(μ‐SCH 2 ) 2 N(CH 2 ) 2 CO 2 ‐3‐C 6 H 4 S 2 C 6 H 4 ‐3′‐O(SubPc)}Fe 2 (CO) 6 ] ( 5 ) and [{(μ‐SCH 2 ) 2 NC 6 H 4 ‐4‐O(SubPc)}Fe 2 (CO) 6 ] ( 8 ), have been synthesized and structurally characterized. The treatment of chlorosubphthalocyanine (SubPc‐Cl, 1 ) with (3‐HOC 6 H 4 S) 2 in toluene gave the corresponding phenoxy‐substituted SubPc derivative 3‐HOC 6 H 4 S 2 C 6 H 4 ‐3′‐O(SubPc) ( 2 ) in 78 % yield, whereas the reaction of in‐situ‐generated [(μ‐HOCH 2 S) 2 Fe 2 (CO) 6 ] ( 3 ) with β‐alanine afforded diiron complex [{(μ‐CH 2 S) 2 N(CH 2 ) 2 CO 2 H}Fe 2 (CO) 6 ] ( 4 ) in 53 % yield. Further treatment of 2 with 4 in the presence of N , N′ ‐dicyclocarbodiimide (DCC) and N , N ‐dimethyl‐4‐aminopyridine (DMAP) in CH 2 Cl 2 resulted in the formation of model compound 5 in 86 % yield. Model compound 8 could be prepared by two methods. One method involves the reaction of in‐situ‐generated 3 with 4‐aminophenol in tetrahydrofuran (THF) to give diiron complex [{(μ‐CH 2 S) 2 NC 6 H 4 OH‐4}Fe 2 (CO) 6 ] ( 6 ) in 61 % yield and further treatment of SubPc‐Cl ( 1 ) with 6 in toluene to give 8 in 13 % yield. The other method involves the reaction of SubPc‐Cl ( 1 ) with silver triflate (AgOTf) followed by treatment of the resulting intermediate SubPc‐OTf ( 7 ) with 6 in the presence of Et 3 N to produce 8 in a much higher yield (59 %). All the new precursors ( 2 , 4 , and 6 ) and the model compounds 5 and 8 have been fully characterized by elemental analysis and various spectroscopy techniques, as well by X‐ray crystallography for 2 , 4 , 6 , and 8 . In addition, the photoinduced H 2 production catalyzed by model 8 was preliminarily investigated.