Die Synthese von cis‐ und trans‐[Fe(CN)₂(CN^tBu)₄] in einer Eintopfreaktion aus Fe₂(CO)₉ und tert. Butylisocyanid

Abstract

Synthesis of cis‐ and trans‐[Fe(CN)2(CNtBu)4] in a One‐Pot Procedure from Fe2(CO)9 and tert. ButylisocyanideThe reaction of Fe2(CO)9 with tert. butyl isocyanide in the presence of 10 bar of carbon monoxide leads to the formation of the mononuclear trigonal bipyramidal compound [Fe(CO)3(CNtBu)2] with two axially coordinated isocyanide ligands. If the same reaction is carried out without additional carbon monoxide being present in the solution, a 1:1 mixture of the isomeric octahedral complexes cis‐ and trans‐[Fe(CN)2(CNtBu)4] is produced via a complex redox reaction involving the reductive cleavage of isocyanide ligands. The molecular structures of the product compounds is going to be discusssed. The crystal structures of cis‐ and trans‐[Fe(CN)2(CNtBu)4] are mainly determined by the ability of the cyano ligands to act as hydrogen bond acceptor sites.

The reaction of manganese carbonyl with tert-butylisocyanide: Synthesis and characterization of cis- and trans-[MnI(tBuNC)4(CN)(CO)]

“…This leads to the isolation of the mononuclear compounds cis-and trans-[Mn( t BuNC) 4 (CN)(CO)] (1a and 1b), in excellent yields. So starting from Mn 2 (CO) 10 the metal atom is only oxidized to the +1-state and not to the +2-state as it was observed for the corresponding reaction of ruthenium and iron carbonyl compounds [2,3]. The IRand MS-data, the elemental analysis (cf.…”

“…In connection with the synthesis of cis-and trans-[Fe( t BuNC) 4 (CN) 2 ] we recognized that this reaction in contrast to the analogous reaction starting from ruthenium carbonyls is only successful if no carbon monoxide is present [3]. So we performed the reaction of Mn 2 (CO) 10 with tert-butyl isocyanide without any additional CO pressure.…”

“…The reaction of Mn 2 (CO) 10 with tert-butylisocyanide proceeds via the oxidation of the transition metal and the concomitant reductive cleavage of the isocyanide in analogy to iron and ruthenium carbonyl compounds [2,3]. The isolated products are depicted in Scheme 1.…”

“…Found: C,58.65;H,8.28;N,15.55%. m.p Table 3 Crystal and intensity data for the compounds 1b, [3][4][5]7 0.08 · 0.08 · 0.04 0.03 · 0.03 · 0.02 0.04 · 0.04 · 0.02 0.04 · 0.04 · 0.03 0.03 · 0.02 · 0.01 0.02 · 0.02 · 0.02 a (Å ) 16.8870 (4) 13.8640 (4) 10.025 (1) 11.6939 (5) 10.1944(9) 9.1484(5) b (Å ) 9.4207 (3) 20.0112 (3) 10.656 (1) 14.5357 (7) 26.976 (2) 12.1727(6) c (Å ) 18.9648 (5) 23.8270 (6) 14.060 (1) 18.389 (1) 12.709 (1) …”

“…Slight modifications of the reaction conditions allow the synthesis of the corresponding iron(II) derivatives from Fe 2 (CO) 9 [3]. The ruthenium complexes have already been introduced to the formation of cyanide bridged coordination polymers.…”