Tangoulis Vasilis, Malamatari Dora A., Soulti Kali, Stergiou Voula, Raptopoulou Catherine P., Terzis Aris, Kabanos Themistoklis A., Kessissoglou Dimitris P.
Department of General & Inorganic Chemistry, Aristotle University of Thessaloniki, 54006 Thessaloniki, Greece, Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 45110 Ioannina, Greece, and NRCPS "Demokritos", Institute of Materials Science, 15310 Aghia Paraskevi Attikis, Greece.
Inorg Chem. 1996 Aug 14;35(17):4974-4983. doi: 10.1021/ic960183j.
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.
通过X射线晶体学对两个混合价态的Mn(III)Mn(II)配合物和一个化学计量比为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)以及Mn(II)Mn(II)Mn(II) (AcO)(6)(pybim)(2) (1b)的同价态锰三核配合物进行了结构表征。其中H(3)saladhp是一种三齿席夫碱配体，pybim是一种中性双齿供体配体。结构表征的混合价态配合物具有晶体学反演对称性所要求的严格180°的Mn(III)-Mn(II)-Mn(III)角。这些配合物是价态捕获的，两个末端Mn(III)离子沿醋酸根或水杨酸根-Mn(III)-X轴呈现 Jahn-Teller 畸变。Mn-Mn间距分别为3.511 Å和3.507 Å。混合价态配合物的基态为S = (3)/(2)，同价态配合物为S = (5)/(2)，具有较小的反铁磁交换J耦合，分别为-5.6和-1.8 cm(-1)，而4 K下的粉末ESR谱显示，对于Mn(III)Mn(II)Mn(III)，在g约为4.3处有一个宽的低场信号，对于Mn(II)Mn(II)Mn(II)，在g = 2处有一个宽的温度依赖信号。1a的晶体数据：[C(36)H(60)O(20)N(2)Cl(2)Mn(3)]，三斜晶系，空间群P&onemacr;，a = 9.272(7) Å，b = 11.046(8) Å，c = 12.635(9) Å，α = 76.78(2)°，β = 81.84(2)°，γ = 85.90(2)°，Z = 1。3a的晶体数据：[C(48)H(56)O(18)N(2)Cl(2)Mn(3)]，单斜晶系，空间群P2(1)/n，a = 8.776(3) Å，b = 22.182(7) Å，c = 13.575(4) Å，β = 94.44(1)°，Z = 2。1b的晶体数据：[C(36)H(36)O(12)N(6)Mn(3)]，三斜晶系，空间群P&onemacr; , a = 13.345(6) Å，b = 8.514(4) Å，c = 9.494(4) Å，α = 75.48(1)°，β = 75.83(1)°，γ = 76.42(1)°，Z = 1。
