Lescop Christophe, Belorizky Elie, Luneau Dominique, Rey Paul
Laboratoire de Chimie Inorganique et Biologique, UMR 5046, DRFMC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09, France.
Inorg Chem. 2002 Jul 1;41(13):3375-84. doi: 10.1021/ic0200038.
This paper reports the synthesis, crystal structures, and magnetic properties of a series of lanthanide complexes with nitronyl nitroxide radicals of general formula [[Ln(III)(radical)(4)] x (ClO(4))(3) x (H(2)O)(x) x (THF)(y)] (1-4) and [Ln(III)(radical)(2)(NO(3))(3)] (5, 6) [Ln = La (compounds 1, 3, 5) or Gd (compounds 2, 4, and 6); radical = 2-(2'-benzymidazolyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (NITBzImH, compounds 1, 2, 5, 6) or 2-[2'-[(6'-methyl)benzymidazolyl]]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (NITMeBzImH, compounds 3, 4)]. (1) C(64)H(88)Cl(3)LaN(16)O(24), fw = 1710.76, orthorhombic, Fddd, a = 11.0682(8) A, b = 34.240(3) A, c = 42.787(3) A, V = 16215(2) A(3), Z = 8, R = 0.0876, R(w) = 0.2336. (2) C(64)H(88)Cl(3)GdN(16)O(24), fw = 1729.10, tetragonal, P 4 macro 2c, a = 16.0682(4) A, b = 16.0682(4) A, c = 18.7190(6) A, V = 4833.0(2) A(3), R = 0.0732, R(w) = 0.2218. (3) C(68)H(94)Cl(3)LaN(16)O(23), fw = 1742.80, tetragonal, P 4 macro 2(1)m, a = 21.125(3) A, b = 21.125(3) A, c = 10.938(2) A, V = 4881.5(14) A(3), R = 0.1017, R(w) = 0.3126. (5) C(28)H(34)LaN(11)O(13), fw = 871.57, orthorhombic, Pna2(1), a = 19.5002(12) A, b = 13.0582(8) A, c = 14.5741(9) A, V = 3711.1(4) A(3), R = 0.0331, R(w) = 0.1146. (6) C(28)H(34)GdN(11)O(13), fw = 889.91, orthorhombic, Pna2(1), a = 19.1831(10) A, b = 13.1600(7) A, c = 14.4107(7) A, V = 3638.0(3) A(3), Z = 4, R = 0.0206, R(w) = 0.0625. Compounds 1-4 consist of M(III)(radical)(4) cations, uncoordinated perchlorate anions, THF, and water crystallization molecules. In these complexes, the coordination number around the lanthanide ion is eight, and the polyhedron is either a distorted dodecahedron (1) or a distorted cube (2, 3). The crystal structures of 5 and 6 consist of independent [M(III)(radical)(2)(NO(3))(3)] entities in which the lanthanide is ten-coordinated and has a distorted bicapped square antiprism coordination polyhedron. For the lanthanum(III) complexes, the temperature dependence of the magnetic susceptibility indicates that radical-radical magnetic interactions are negligible either for compounds 1 and 3, while for compound 5 it is simulated considering dimers of weakly antiferromagnetically coupled radicals (J(rad-rad) = -1.1 cm(-1)). In the case of the gadolinium(III) compounds (2, 4, 6), each magnetic behavior gives unambiguous evidence of antiferromagnetic Gd(III)-radical interaction (2, J(Gd-rad) = -1.8 cm(-1); 4, J(Gd-rad) = -3.8 cm(-1); 6, J(Gd-rad1) = -4.05 cm(-1) and J(Gd-rad2) = -0.80 cm(-1)), in contrast to the ferromagnetic case generally observed. The nature of the Gd(III)-radical interaction is explained in relation to the donor strength of the free radical ligand.
本文报道了一系列通式为[[Ln(III)(自由基)(4)] x (ClO(4))(3) x (H(2)O)(x) x (THF)(y)] (1 - 4)和[Ln(III)(自由基)(2)(NO(3))(3)] (5, 6)的镧系元素与硝酰基氮氧化物自由基配合物的合成、晶体结构及磁性质[Ln = La (化合物1、3、5)或Gd (化合物2、4、6); 自由基 = 2-(2'-苯并咪唑基)-4,4,5,5-四甲基咪唑啉-1-氧基-3-氧化物(NITBzImH, 化合物1、2、5、6)或2-[2'-[(6'-甲基)苯并咪唑基]]-4,4,5,5-四甲基咪唑啉-1-氧基-3-氧化物(NITMeBzImH, 化合物3、4)]。(1) C(64)H(88)Cl(3)LaN(16)O(24), 分子量 = 1710.76, 正交晶系, Fddd, a = 11.0682(8) Å, b = 34.240(3) Å, c = 42.787(3) Å, V = 16215(2) Å(3), Z = 8, R = 0.0876, R(w) = 0.2336。(2) C(64)H(88)Cl(3)GdN(16)O(24), 分子量 = 1729.10, 四方晶系, P 4 2c, a = 16.0682(4) Å, b = 16.0682(4) Å, c = 18.7190(6) Å, V = 4833.0(2) Å(3), R = 0.0732, R(w) = 0.2218。(3) C(68)H(94)Cl(3)LaN(16)O(23), 分子量 = 1742.80, 四方晶系, P 4 2(1)m, a = 21.125(3) Å, b = 21.125(3) Å, c = 10.938(2) Å, V = 4881.5(14) Å(3), R = 0.1017, R(w) = 0.3126。(5) C(28)H(34)LaN(11)O(13), 分子量 = 871.57, 正交晶系, Pna2(1), a = 19.5002(12) Å, b = 13.0582(8) Å, c = 14.5741(9) Å, V = 3711.1(4) Å(3), R = 0.0331, R(w) = 0.1146。(6) C(28)H(34)GdN(11)O(13), 分子量 = 889.91, 正交晶系, Pna2(1), a = 19.1831(10) Å, b = 13.1600(7) Å, c = 14.4107(7) Å, V = 3638.0(3) Å(3), Z = 4, R = 0.0206, R(w) = 0.0625。化合物1 - 4由M(III)(自由基)(4)阳离子、未配位的高氯酸根阴离子、THF和水结晶分子组成。在这些配合物中，镧系离子周围的配位数为8，多面体要么是扭曲的十二面体(1)，要么是扭曲的立方体(2, 3)。5和6的晶体结构由独立的[M(III)(自由基)(2)(NO(3))(3)]实体组成，其中镧系元素为十配位，具有扭曲的双帽四方反棱柱配位多面体。对于镧(III)配合物，磁化率的温度依赖性表明，对于化合物1和3，自由基 - 自由基磁相互作用可忽略不计，而对于化合物5，考虑到弱反铁磁耦合自由基的二聚体进行了模拟(J(rad - rad) = -1.1 cm(-1))。对于钆(III)化合物(2, 4, 6)，每种磁行为都明确证明了反铁磁Gd(III) - 自由基相互作用(2, J(Gd - rad) = -1.8 cm(-1); 4, J(Gd - rad) = -3.8 cm(-1); 6, J(Gd - rad1) = -4.05 cm(-1)和J(Gd - rad2) = -0.80 cm(-1))，这与通常观察到的铁磁情况相反。Gd(III) - 自由基相互作用的性质与自由基配体的供体强度有关。
