As active site models of [Fe]-lydrogenase, tridentate 2-acylmethyl-6-methoxymethoxy-difunctionalized pyridine-containing complexes eta(3)-(2-COCH2-6-MeOCH2OC5H3N)Fe(CO)(2)(L-1) (4, L-1 = I; 5, SCN; 6, PhCS2) were prepared via the following multistep reactions: (i) etherification of 2-MeO2C-6-HOC5H3N with C1CH(2)OMe to give 2-MeO2C-6-MeOCH2OC5H3N (1), (ii) reduction of 1 with NaBH4 to give 2-HOCH2-6-MeOCH2OC5H3N (2), (iii) esterification of 2 with 4-toluenesulfonyl chloride to give 2-TsOCH2-6-MeOCH2OC5H3N (3), (iv) nucleophilic substitution of 3 with Na2Fe(CO)(4) followed by treatment of the resulting Fe(O) intermediate Na[(2-CH2-6-MeOCH2OC5H3N)Fe(CO)(4)] (M-1) with I-2 to give complex 4, and (v) condensation of 4 with KSCN and PhCS2K to give complexes 5 and 6, respectively. In contrast to the preparation of complexes 4-6, bidentate 2-acylmethyl-6-methoxymethoxy-difunctionalized pyridine-containing model complexes eta(2)-(2-COCH2-6-MeOCH2OC5H3N)Fe(CO)(2)(I)(L-2) (7, L-2 = PPh3; 8, Cy-C6H11NC) and eta(2)-(2-COCH2-6-MeOCH2OC5H3N)Fe(CO)(2)(L-3) (9, L-3 = 2-SC5H4N; 10, 8-SC9H6N) were prepared by ligand exchange reactions of 4 with PPh3, Cy-C6H11NC, 2-KSC5H4N, and 8-KSC9H6N, respectively. Particularly interesting is that the tridentate 2,6-bis(acylmethyl)pyridine-and 2-acylmethyl-6-arylthiomethylpyridine-containing model complexes eta(3)- [2,6-(COCH2)(2)C5H3N]Fe(CO)(2)(1,4) (11, L-4 = PPh3; 12, CO) and eta 3-2-(COCH2-6-ArSCH2C5H3N)Fe(CO)(2)(ArS) (13, ArS = PhS; 14, 2-S-S-MeC4H2O) were obtained, unexpectedly, when 2,6-(TsOCH2)(2)C5H3N reacted with Na2Fe(CO)(4) followed by treatment of the resulting mixture with ligands PPh3 and CO or disulfides (PhS)(2) and (2-S-5MeC(4)H(2)O)(2). Reactions of ligand precursors 3 and 2,6-(TsOCH2)(2)C5H3N with Na2Fe(CO)(4) were monitored by in situ IR spectroscopy, and the possible pathways for producing complexes 4 and 11-14 via intermediates Na[(2-CH2-6-MeOCH2OC5H3N)Fe(CO)(4)] Na[(2-CH2-6-TsOCH2C5H3N)Fe(CO)(4)] (M-2), and (2-COCH2-6-CH2C5H3N)Fe(CO)(3) (M3) are suggested. New compounds 1-14 were characterized by elemental analysis, spectroscopy, and, for some of them, X-ray crystallography.