Crystal structure of 1,6-di(ferrocenyl)-3,4-dihydroxy-hexa-2,4-diene- 1,6-dion, Fe2(C5H5)2(C16H12O4)

Abstract

Source of materialThe title complex was synthesized from acetylferrocene, potassium hydride and diethyloxalate in thf, as described in [1]. Violet plates were obtained from a concentrated solution of the title compound in dichloromethane. DiscussionThe title molecule Fe 2(C5H5)2(C16H12O4) 1 possesses an inversion centre (figure). The bond lengths and bond angles clearly show that the title complex has also in the solid state the keto enol structure and that the two hydroxy groups are in 3,4 positions of the hexadiene-dion rather than in 1,6. Important bond lengths and bond angles are:The bond lengths in 1 are very similar to those in a bis(palladium) complex of the dianion of 1-with the exception that in that complex the four C-O distances are almost identical (1.282(4) Å, 1.279(4) Å), as expected. In the structure of 1, there is no symmetrical hydrogen bridge between the carbonyl groups. The bond length of O2-H82 is 0.88(3) Å while the distance between H82 and the acceptor O1 is 1.70(3) Å. The bond angle ÐO2-H82-O1 is 155(3)°. The angles between the least-square plane of O1, O2, C6, C7, and C8 and the C 5H5 units are 9.58 (13)

Syntheses and Crystal Structures of Two Ferrocenyl Enamine Esters

“…Ethyl 2, 4-dioxo-4-ferrocenyl-butanoate, C 5 H 5 FeC 5 H 4 COCH 2 COCO 2 CH 2 CH 3 , was synthesized by a literature method [13][14][15]. Progress of reactions was monitored by TLC.…”