Treatment of 3,4-(ClC(O))₂-^cC₄H₂S (1) with [FcCH₂OLi] (2-Li) (Fc = Fe(η⁵-C₅H₅)(η⁵-C₅H₄)) in a 1:2 ratio gave 3,4-(FcCH₂OC(O))₂-^cC₄H₂S (3). Compound 3 decomposes in solution during crystallization to produce FcCH₂OH (2) along with 3,4-thiophenedicarboxylic anhydride (4). The cyclic voltammogram of 3 exhibits a reversible ferrocene-related redox couple (E_1/2 = 108 mV, vs. Cp₂Fe/Cp₂Fe⁺) using [NⁿBu₄] [B(C₆F₅)₄] as the supporting electrolyte. DFT calculations reveal that the energy values of the LUMO orbitals of 3 (3,4-thiophene core) show 1 eV higher energies than that one of 2,5-(FcCH₂OC(O))₂-^cC₄H₂S (5), both compounds’ HOMO orbitals are close to each other. Compound 4 was characterized by single X-ray structure analysis. It forms a band-type structure based on intermolecular O1···S1 interactions being parallel to (110) and (1–10) in the solid state, while electrostatic C···O interactions between the C=O functionalities of adjacent molecules connect both 3D-networks. Hirshfeld surface analysis was used to gain more insight into the intermolecular interactions in 4, the enrichment ratios (E) suggest that O···H, S···S, and O···C are the most favored intermolecular interactions, as shown by E values above 1.20. The relevance of the weak O···H, O···O, and O···C contacts in stabilizing the molecular structure of 4 was highlighted by the interaction energies between molecular pairs.

A novel series of palladium( ii ) coordination complexes of the formula [Pd(CH ₃ C(NAr)CHC(O)CH ₃ ) ₂ ] (4a–j) were synthesized by the reaction of enaminone ligands (3a–j) with [PdCl ₂ (NCCH ₃ ) ₂ ] in a molar ratio of 2 : 1 in the presence of ^t BuOK.