Distortions of the coordination polyhedron in high-spin manganese(III) complexes. 2. Crystal structure of thiocyanatobis(acetylacetonato)manganese(III)

Abstract

The crystal structure of thiocyanatobis(acetylacetonato)manganese(III), Mn(0zC5H7)z(NCS), has been determined by single-crystal X-ray diffraction techniques and refined anisotropically for all nonhydrogen atoms by full-matrix least-squares techniques to R I = 0.057 and Rz = 0.061 by using 1917 independent diffractometer-recorded reflections (Nb-filtered Mo K, radiation and 8-28 scans) having 28MoK& < 55" and I > 2a(I). The compound crystallizes in the uniquely determined centrosymmetric orthorhombic space group Pbca with eight molecules in a unit cell of dimensions a = 13.422 (2) A, b = 14.519 (3) A, and c = 13.763 (3) 8, (pcalcd = 1.541 g/cm3, &,bad = 1.540 g/cm3). Each thiocyanato ligand bridges two adjacent quasi-planar Mn(acac)z* groups in the three-dimensional lattice by using the glide operator perpendicular to the c'axis of the unit cell to generate infinite chains of octahedral Mn(II1) subunits along the 2 axis. The octahedral coordination polyhedron is tetragonally elongated and approximates idealized C , symmetry with the trans-coordinated thiocyanato nitrogen and sulfur atoms on the pseudo-fourfold axis. The four "short" Mn-0 bonds have average lengths of 1.912 (4) 8, while the two long trans Mn-N and Mn-S' bonds to the ends of bridging thiocyanato ligands have lengths of 2.189 (5) and 2.880(2) A, respectively. The dissimilarity of the two ends of the thiocyanato ligand has a pronounced effect on the Mn coordination geometry in this complex. The Mn atom is displaced by 0.12 8, from the mean plane of the quasi-square of four coordinated oxygen atoms toward the coordinated thiocyanato nitrogen atom.

Bis(acetylacetonato-κ2O,O′)(methanol-κO)(thiocyanato-κN)manganese(III)

“…The distance of Mn-O methanol [2.289 (5) Å] is obviously longer than the bond lengths of Mn-O acetylacetonate . The bond length of Mn-N SCN is 2.187 (6) Å, which is also consistent with that found in [Mn(acac) 2 (SCN)] (Stults et al, 1979). In the crystal structure, a molecular chain along the [101] direction is formed by an intermolecular H-bond between the O atom of the methanol molecule and the S atom of the SCNion (Table 1).…”

“…For the synthesis, see: Stults et al (1975). For related structures, see: Stults et al (1979); Swarnabala et al (1994).…”

Novel complexes of Mn(III) with macrocylic porphine ligand and ethylenediamine

“…All Mn(III) porphyrin syntheses were based on an adaptation of combined literature methods [25,26]. The bis(acetylacetonato) Mn(III) complexes with axial halo-or pseudo-halo groups, i.e.…”

Synthesis, X‐ray Crystal Structures, and Spectroscopic, Electrochemical, and Theoretical Studies of MnIII Complexes of Pyridoxal Schiff Bases with Two Diamines

“…[13,14] The Mn-O and Mn-N bond lengths observed in this molecule [as well as those generally observed for Mn III (salen)type complexes] are appreciably shorter than the corresponding bond lengths in [Mn III (EDTA)] 1-(EDTA = ethylenediaminetetraacetate), [Mn III (acac) 2 (N 3 )] n (acac = acetylacetonate), and [Mn III (trop) 3 ] (trop = tropalonate). [20][21][22] Scheme 2. Mn III salen/salpn complexes mentioned in Table 3; dcsalen = N,NЈ-bis (3,5-dichlorosalicylidene)ethane-1,2-diamine; bsalen = N,NЈ-bis(5-bromosalicylidene)ethane-1,2-diamine; salpn = bis(salicylidene)propane-1,3-dimaine; ophensal = bis(salicylidene)-1,2-diaminobenzene.…”