Manganese(II/II/II) and Manganese(III/II/III) Trinuclear Compounds. Structure and Solid and Solution Behavior

Abstract

Two mixed-valence Mn(III)Mn(II) complexes and a homo-valence Mn(II) trinuclear manganese complex of stoichiometry Mn(III)Mn(II)Mn(III)(5-Cl-Hsaladhp)(2)(AcO)(4)(MeOH)(2).4CH(3)OH (1a), Mn(III)Mn(II)Mn(III) (Hsaladhp)(2)(AcO)(2)(5-Cl-Sal)(2)(thf)(2) (3a) and Mn(II)Mn(II)Mn(II) (AcO)(6)(pybim)(2) (1b) where H(3)saladhp is a tridentate Schiff base ligand and pybim a neutral bidentate donor ligand, have been structurally characterized by using X-ray crystallography. The structurally characterized mixed-valence complexes have strictly 180 degrees Mn(III)-Mn(II)-Mn(III) angles as required by crystallographic inversion symmetry. The complexes are valence trapped with two terminal Mn(III) ions showing Jahn-Teller distortion along the acetate or salicylate-Mn(III)-X axis. The Mn.Mn separation is 3.511 Å and 3.507 Å respectively. The mixed-valence complexes have S = (3)/(2) ground state and the homovalence complex S = (5)/(2), with small antiferromagnetic exchange J couplings, -5.6 and -1.8 cm(-1), respectively, while the powder ESR spectra at 4 K show a broad low field signal with g approximately 4.3 for Mn(III)Mn(II)Mn(III) and a broad temperature-dependent signal at g = 2 for Mn(II)Mn(II)Mn(II). Crystal data for 1a: [C(36)H(60)O(20)N(2)Cl(2)Mn(3)], triclinic, space group P&onemacr;, a = 9.272(7) Å, b = 11.046(8) Å, c = 12.635(9) Å, alpha = 76.78(2) degrees, beta = 81.84(2) degrees, gamma = 85.90(2) degrees, Z = 1. Crystal data for 3a: [C(48)H(56)O(18)N(2)Cl(2)Mn(3)], monoclinic, space group P2(1)/n, a = 8.776(3) Å, b = 22.182(7) Å, c = 13.575(4) Å, beta = 94.44(1) degrees, Z = 2. Crystal data for 1b: [C(36)H(36)O(12)N(6)Mn(3)], triclinic, space group P&onemacr;, a = 13.345(6) Å, b = 8.514(4) Å, c = 9.494(4) Å, alpha = 75.48(1) degrees, beta = 75.83(1) degrees, gamma = 76.42(1) degrees, Z = 1.

Versatility in the Coordination Modes of n‐Chlorobenzoato Ligands: Synthesis, Structure and Magnetic Properties of Three Types of Polynuclear MnII Compounds

“…There are some trinuclear compounds with a [Mn 3 (µ-RCOO) 6 ] core reported in the literature, [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] but only half of them are magnetically studied, [13][14][15][16][17][18][19][20][21][22] and even less have been characterized by EPR spectroscopy. [19][20][21][22][23] The number of described 1D Mn II chains with two carbox-4471 -2.8, -1.8 and -3.6 cm -1 for compounds 1-5, respectively. Each type of compound may be distinguished by their characteristic EPR spectrum at 4 K. Fairly good simulations of the spectra at 4 K for the trinuclear compounds 1-3 were obtained with ground state ZFS parameters, D 5 ylate bridges is few; [21][22][24][25][26][27][28][29][30][31][32]…”

Synthesis and Characterisation of Novel (Guanidine)manganese Complexes and Their Application in the Epoxidation of 1‐Octene

“…[22] The Mn···Mn distances of C3 and C4 are with 3.545(1) (C3) and 3.576(1) Å (C4) in the range of analogous complexes. [4,18,21,22] The described [Mn 3 (CH 3 COO) 6 ] unit is also part of the polymeric Mn(CH 3 COO) 2 ·4H 2 O structure, but here the second oxygen of the monodentate bridging acetato ligand coordinates to a manganese atom of a further [Mn 3 (CH 3 COO) 6 ] unit. [23] Figure 5.…”

“…This is in accordance with the "carboxylate shift" described by Lippard et al [20] The Mn(1)-O(5) bond in C3 is one of the shortest and the Mn(1)-O(6) bond belongs to the largest for this binding motif. [4,18,21,22] Remarkable is that in [Mn 3 (pybim) 2 (CH 3 COO) 6 ] the Mn-O bond to the bridging oxygen atom is also very short (2.132 Å), but the Mn···O distance of the free oxygen atom is notably larger (2.823 Å) than in C3. [22] The Mn···Mn distances of C3 and C4 are with 3.545(1) (C3) and 3.576(1) Å (C4) in the range of analogous complexes.…”

“…[4,18,21,22] Remarkable is that in [Mn 3 (pybim) 2 (CH 3 COO) 6 ] the Mn-O bond to the bridging oxygen atom is also very short (2.132 Å), but the Mn···O distance of the free oxygen atom is notably larger (2.823 Å) than in C3. [22] The Mn···Mn distances of C3 and C4 are with 3.545(1) (C3) and 3.576(1) Å (C4) in the range of analogous complexes. [4,18,21,22] The described [Mn 3 (CH 3 COO) 6 ] unit is also part of the polymeric Mn(CH 3 COO) 2 ·4H 2 O structure, but here the second oxygen of the monodentate bridging acetato ligand coordinates to a manganese atom of a further [Mn 3 (CH 3 COO) 6 ] unit.…”

Synthesis, Crystal Structure, and Magnetic Properties of Two Manganese(II) Polymers Bearing Ferrocenecarboxylato Ligands

“…The Mn-O bond lengths of complex 1 are in the range 2.035(2)-2.227(3) Å (Table 1), which is comparable to those in related complexes. [3,12] The O-Mn-O angles range from 83.18 to 180.0° (Table 1). An interesting feature is the construction of the [Mn 2 (FcCO 2 ) 4 ] building block as shown in Figure 2.…”