Diphosphor, phosphor-, arsen- und antimonatome als clusterbaugruppen

Synthesis, Structure, and Reactivity of a Diphosphadiferratetrahedrane with a Fe−Fe Double Bond

“…Compound 4 has 5 SEPs; thus, one less than 2. [2] The FeÀFe bond length of 2.3944(10) lies in the range for FeÀFe double bonds and is slightly longer than that in 1 (2.32 ), but considerably shorter than that in 2 (2.605 ). [3]), which is therefore slightly shorter than that in 2 (2.09 ).…”

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Dedicated to Professor Marianne Baudler on the occasion of her 80th birthday

Whereas in the chemistry of acetylene complexes of iron, compound 1 containing a C 2 Fe 2 tetrahedrane framework and a Fe À Fe double bond was prepared and crystallographically characterized already in 1976, [1] for the iso(valence)electronic and isolobal (HC 23 P, HCCH : PP : ) diphosphadiferratetrahedranes only the complex 2 with a FeÀFe single bond and additional P-coordination is known. [2] Diphosphadimetallatetrahedranes of the type [{L n M} 2 -(m-h 2 :h 2 -P 2 )] (L n M 15 valence-electron(VE) fragment) [3] synthesized to date all display M À M single bonds, and with six skeleton electron pairs (SEPs) for the tetrahedral M 2 P 2 framework are considered as nido clusters. According to theoretical investigations a decrease (5 SEPs) as well as an increase (7 SEPs) in the number of electrons in the skeleton lead to changes of the M 2 P 2 framework.

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Crystallographic and Structural Analysis of Iron Heterometallic Compounds Part IV: Heteropentameric Compounds

“…Structure of deep-red Fe 3 Mn 2 cluster [25] is similar to that of Fe 4 Cr cluster [25]. The Fe -Fe bond distances in the Fe -Fe triangle range from 2.608(6) to 2.671(6)A.…”

“…The internal dihedral angle of Fe 4 butterfly framework of 71.7° is the smallest one in the series of Fe 4 Au clusters. The red Fe 4 Cr cluster [25] is the only example with a chromium atom. The cluster contains the trigonal bipyramidal cluster framework Fe 3 (CO)9^3-P) 2 , the basis of which is a closed triangle formed by three Fe(CO)3 units; the apical positions of the trigonal bipyramid are occupied by phosphorus atoms.…”

Skeletal isomerism in mixed transition-metal/main-group closo clusters

“…Going to the E = N species leads to a switching in the isomer relative stabili- Table 3 Relative energies (kcal/mol) of skeletal isomers A, B and C for the 6-SEP closo clusters M 3 E 2 (CO) 9 Table 4 Major optimized averaged interatomic distances (Å) for the three skeletal isomers of the M 3 E 2 (CO) 9 (M = Fe, Ru; E = Bi, N, P, N, AsH + , PH + , NH + , S + , Se + , CH, SiH, BH -) series. Available experimental values for related species are given in parentheses [8]. e Fe 3 (CO) 9 (C 2 Ph 2 ) [12].…”