Reductive Carbonylation Synthesis of Metal Carbonyls. II. Synthesis of Manganese Carbonyl and Group VI-B Metal Carbonyls by the Alkylaluminum Method¹

Heterobimetallic Chromium Manganese Carbonyl Nitrosyls: Comparison with Isoelectronic Homometallic Binuclear Chromium Carbonyl Nitrosyls and Manganese Carbonyls

“…Since it was discovered in 1954 [1], dimanganese decacarbonyl Mn 2 (CO) 10 has been studied extensively [2][3][4][6][7][8][9][10][11][12][36][37][38][39][40][41][42][43][44]. The following three structures were studied for Mn 2 (CO) 10 [13]:…”

“…We have found 12 stationary points for the CrMn(NO)(CO) 8 stoichiometry, corresponding to the three kinds of previously studied [13] structures for Mn 2 (CO) 9 , namely (a) the singly bridged (OC) 4 Mn(η 2 -µ-CO)Mn(CO) 4 structures, (b) the unbridged (OC) 5 Mn-Mn(CO) 4 structures, and (c) the triply bridged (OC) 3 Mn(µ-CO) 3 Mn(CO) 3 structures ( Figure 4 and Table 1) [13]. The C s singly nitrosyl-bridged structure (OC) 4 Mn(µ-NO)Cr(CO) 4 8-1S has the lowest energy and all real harmonic vibrational frequencies, suggesting it to be the global minimum of CrMn(NO)(CO) 8 .…”

“…The isoelectronic bimetallic molecules Mn 2 (CO) 10 and Cr 2 (NO) 2 (CO) 8 have been known for some time [1]. Thus, Mn 2 (CO) 10 can be synthesized by the reductive carbonylation of manganese(II) derivatives using sodium benzophenone ketyl [2] or triisobutylaluminum [3] as the reducing agent at elevated carbon monoxide pressure. In addition, an atmospheric pressure synthesis of Mn 2 (CO) 10 is possible using the reductive carbonylation of the formerly (but not now) readily available (η 5 -MeC 5 H 4 )Mn(CO) 3 with sodium metal in diglyme solution [4].…”

“…Thus, Mn 2 (CO) 10 can be synthesized by the reductive carbonylation of manganese(II) derivatives using sodium benzophenone ketyl [2] or triisobutylaluminum [3] as the reducing agent at elevated carbon monoxide pressure. In addition, an atmospheric pressure synthesis of Mn 2 (CO) 10 is possible using the reductive carbonylation of the formerly (but not now) readily available (η 5 -MeC 5 H 4 )Mn(CO) 3 with sodium metal in diglyme solution [4]. The isoelectronic Cr 2 (NO) 2 (CO) 8 can be synthesized by oxidation of the Cr(NO)(CO) 4 − anion with [(C 6 H 5 ) 3 C] + [BF 4 ] − [5].…”

“…In addition, an atmospheric pressure synthesis of Mn 2 (CO) 10 is possible using the reductive carbonylation of the formerly (but not now) readily available (η 5 -MeC 5 H 4 )Mn(CO) 3 with sodium metal in diglyme solution [4]. The isoelectronic Cr 2 (NO) 2 (CO) 8 can be synthesized by oxidation of the Cr(NO)(CO) 4 − anion with [(C 6 H 5 ) 3 C] + [BF 4 ] − [5]. X-ray crystallography shows both Mn 2 (CO) 10 and Cr 2 (NO) 2 (CO) 8 to have analogous unbridged structures with all of the CO and NO ligands in terminal positions and a formal metal-metal single bond joining two halves of the molecule (Figure 1) [5][6][7][8].…”