Characterization of open clusters with linked germanium-diiron or diiron-tin triangles: structures of Ge2Fe6(CO)23, Sn2Fe6(CO)23 and Ge2Fe7(CO)26

Transformations in Transition-Metal Carbonyls Containing Arsenic: Exploring the Chemistry of [Et4N]2[HAs{Fe(CO)4}3] in the Search for Single-Source Precursors for Advanced Metal Pnictide Materials

“…The CO-bridged Fe–Fe bond is short at 2.6051(18) Å, although it is consistent with the other known examples of an {Fe 2 (CO) 7 H} group (average 2.585(15) Å including that of [ IV ] − ). − The Fe–Mn bond is much longer at 2.8191(15) Å, though consistent with other M–M bonds in M 2 (CO) 8 spirocyclic environments (average 2.816(44) Å). ,− The average arsenic bond distance to the {Fe 2 (CO) 7 H} fragment is 2.377(6) Å, while the As–Fe/Mn distances are slightly shorter at 2.3647(2) Å, likely due to less strain in the FeMn­(CO) 8 moiety. The bond distance of the CO bond in the bridging carbonyl (C120–O120) of 1.132(4) Å appears to be shorter than the respective bridging carbonyls of the other known {Fe 2 (CO) 7 H} groups (average of 1.182(12) Å). − …”

“…X is a neutral molecule and obeys the 18-electron rule. The average M–M bond is 2.821(25) Å, similar to 2.816(44) Å, the average M–M bond distance for a variety of spirocyclic EM 2 (CO) 8 compounds where M were first-row transition metals. ,− It was also similar to the 2.8191(15) Å observed in [ VII ] − . Table gives a comparison of X to all known E­{Fe 2 (CO) 8 } 2 clusters where E is a main-group atom (E = Si, Ge, In, Sn, Pb).…”

“…[ VII ] − and X belong to a general class of metal carbonyl clusters in which two M 2 units, each containing a metal–metal bond, are bound to a central main-group atom, a well-known configuration (Figure ). − Both [ VII ] − and X contain three Fe atoms and one Mn atom divided between two M 2 fragments (Figures and ). [ VII ] − and X each possess an MnFe­(CO) 8 fragment as well as a diiron unit which is (μ-H)­Fe 2 (CO) 6 (μ-CO) − and Fe 2 (CO) 8 for [ VII ] − and X , respectively.…”

Replacement of CO ligands by the isolobal gallium(I) compound GaR [R = C(SiMe3)3], formation of the transition metal gallium compounds Mn2(CO)8(μ-GaR)2 and Fe3(CO)9(μ-CO)(μ-GaR)2

“…Thus, a rare example of a triiron compound is formed, in which the Fe 3 core is bridged by three µ-ligands. 15 This unusual structure may be determined by steric factors, and the short Ga-Fe and Ga-C distances force the GaR groups to occupy different Fe-Fe edges. In the case of the common bridging of only one edge, the approach of the bulky C(SiMe 3 ) 3 substituents would result in considerable steric stress in the molecule, which owing to the longer separations of the central atoms is much smaller with the indium analogue.…”

New chemical and stereochemical applications of organoiron complexes

“…In series of iron clusters, this class includes alkylidene [ 715 ], acetylene [ 716 – 718 ], carbide [ 719 ], and phosphaalkyne [ 720 ] bridging ligands. Recent work on mixed-metal clusters comprises Fe-Hg [ 721 ], Fe-Sn [ 722 ], F-Ge [ 723 ], Fe-Co [ 724 ], Fe-Ru [ 725 ], and Fe-Pt [ 726 ] clusters. A novel coordination behavior of ynamine ligands RC = CNR 2 in diiron cluster complexes has been described [ 727 , 728 ]; some of these clusters incorporate carbene ligands [ 728 ].…”