Manganese carbonyl and organometallic compounds: Analysis and classification of crystallographic and structural data

Manganese Coordination Compounds: Classification and Analysis of Crystallographic and Structural Data

“…The linkage is via one μ3-0" 2 anion in each (becoming μ^-Ο). These are seen in the Figure as Mn(l)-0(6') and Mn(l')-0 (6). The dihedral angle between the two Mn 3 planes within each butterfly is 162.15°.…”

“…While there is no crystallographically imposed symmetry element, a pseudo 2-fold rotation axis coincident with the Mn(l)-0(5) is discernable, which relates the following Fig. 13: Structure of [Mn 9 (0) 7 (bz) 13 (8) and Mn(9); Mn (6) and (Mn(7); Mn(3) and Mn(4); Mn (2) and Mn (5). All seven of the oxy bridging groups are of the μ 3 variety.…”

“…There are only three examples in which six-coordination is achieved by six mono-functional ligands /190, 209-211/. While the cation in [Mn(urea) 6 ] +3 /190/ has site symmetry 3, which requires the six Mn-O bonds to be equivalent (198.6(7) pm) in apparent violation of the Jahn-Teller effect, the remaining two species /209-211/ have the same chromophore of MnF 4 02 with a tetragonal bipyramidal geometry, axially elongated as predicted by the JahnTeller theorem.…”

A Manganese Nanosheet: New Cluster Topology and Catalysis

“…An effective magnetic moment m eff of 4.28 m B (or 2.29 cm 3 mol À1 K, per Mn 6 cluster,i nC 6 D 6 ) was recorded, which is much lower than the spin-only value for six uncoupled S = 5/2 spins (14.49 m B or 26.25 cm 3 mol À1 K). [7,9,10] Two-dimensional Mn clusters are very rare; [11] no carbonyl-free 2D hexametal skeleton has ever been reported. Indeed, c M T drops rapidly and approaches zero at low temperatures,which supports the assumption of strong antiferromagnetic exchange and ad iamagnetic ground state.C oupling constants were obtained from fitting the data on the basis of as implified spin Hamiltonian that includes two coupling constants and Zeeman splitting, using the PHI program.…”

“…[3] The unprecedented planar growth might be adirect consequence of the steric bulk of the hmds ligands,which effectively shield the half spaces above and below the metal plane.The Mn À Mn bond lengths (2.85622(3)-2.97627(3) )a re in the range of Mn À Mn bonds in other Mn clusters. [7,11] Thep ositions of the hydride ligands of 2 were determined from the electron density Fourier map.F our m 3 -H atoms coordinate the Mn 6 core in alternating up and down fashion. Tw o m 2 -H atoms span the sterically more hindered peripheral Mn À Mn bonds whereas the least hindered peripheral Mn À Mn edges are coordinated by the bulky hmds ligands.…”