Syntheses, Crystal Structures, and Magnetic Properties of One-Dimensional Oxalato-Bridged Co(II), Ni(II), and Cu(II) Complexes with n-Aminopyridine (n = 2-4) as Terminal Ligand
详细信息 查看全文
- 作者：Oscar Castillo ; Antonio Luque ; Pascual Romá ; n ; Francesc Lloret ; and Miguel Julve
- 刊名：Inorganic Chemistry
- 出版年：2001
- 出版时间：October 22, 2001
- 年：2001
- 卷：40
- 期：22
- 页码：5526 - 5535
- 全文大小：166K
- 年卷期：v.40,no.22(October 22, 2001)
- ISSN：1520-510X
文摘
The reaction of M(ox)·2H2O (M = Co(II), Ni(II)) or K2(Cu(ox)2)·2H2O (ox = oxalate dianion) with n-ampy(n = 2, 3, 4; n-ampy = n-aminopyridine) and potassium oxalate monohydrate yields one-dimensional oxalato-bridged metal(II) complexes which have been characterized by FT-IR spectroscopy, variable-temperature magneticmeasurements, and X-ray diffraction methods. The complexes M(
-ox)(2-ampy)2 (M = Co (1), Ni (2), Cu (3))are isomorphous and crystallize in the monoclinic space group C2/c (No. 15), Z = 4, with unit cell parametersfor 1 of a = 13.885(2) Å, b = 11.010(2) Å, c = 8.755(1) Å, and 
= 94.21(2)
. The compounds M(-ox)(3-ampy)2·1.5H2O (M = Co (4), Ni (5), Cu (6)) are also isomorphous and crystallize in the orthorhombic spacegroup Pcnn (No. 52), Z = 8, with unit cell parameters for 6 of a = 12.387(1), b = 12.935(3), and c = 18.632(2)Å. Compound Co(-ox)(4-ampy)2 (7) crystallizes in the space group C2/c (No. 15), Z = 4, with unit cell parametersof a = 16.478(3) Å, b = 5.484(1) Å, c = 16.592(2) Å, and = 117.76(1). Complexes M(-ox)(4-ampy)2(M = Ni (8), Cu (9)) crystallize in the orthorhombic space group Fddd (No. 70), Z = 8, with unit cell parametersfor 8 of a = 5.342(1), b = 17.078(3), and c = 29.469(4) Å. All compounds are comprised of one-dimensionalchains in which M(n-ampy)22+ units are sequentially bridged by bis-bidentate oxalato ligands with M···M intrachaindistances in the range of 5.34-5.66 Å. In all cases, the metal atoms are six-coordinated to four oxygen atoms,belonging to two bridging oxalato ligands, and the endo-cyclic nitrogen atoms, from two n-ampy ligands, buildingdistorted octahedral surroundings. The aromatic bases are bound to the metal atom in cis (1-6) or trans (7-9)positions. Magnetic susceptibility measurements in the temperature range of 2-300 K show the occurrence ofantiferromagnetic intrachain interactions except for the compound 3 in which a weak ferromagnetic coupling isobserved. Compound 7 shows spontaneous magnetization below 8 K, which corresponds to the presence of spincanted antiferromagnetism.
-ox)(2-ampy)2 (M = Co (1), Ni (2), Cu (3))are isomorphous and crystallize in the monoclinic space group C2/c (No. 15), Z = 4, with unit cell parametersfor 1 of a = 13.885(2) Å, b = 11.010(2) Å, c = 8.755(1) Å, and = 94.21(2). The compounds M(-ox)(3-ampy)2·1.5H2O (M = Co (4), Ni (5), Cu (6)) are also isomorphous and crystallize in the orthorhombic spacegroup Pcnn (No. 52), Z = 8, with unit cell parameters for 6 of a = 12.387(1), b = 12.935(3), and c = 18.632(2)Å. Compound Co(-ox)(4-ampy)2 (7) crystallizes in the space group C2/c (No. 15), Z = 4, with unit cell parametersof a = 16.478(3) Å, b = 5.484(1) Å, c = 16.592(2) Å, and = 117.76(1). Complexes M(-ox)(4-ampy)2(M = Ni (8), Cu (9)) crystallize in the orthorhombic space group Fddd (No. 70), Z = 8, with unit cell parametersfor 8 of a = 5.342(1), b = 17.078(3), and c = 29.469(4) Å. All compounds are comprised of one-dimensionalchains in which M(n-ampy)22+ units are sequentially bridged by bis-bidentate oxalato ligands with M···M intrachaindistances in the range of 5.34-5.66 Å. In all cases, the metal atoms are six-coordinated to four oxygen atoms,belonging to two bridging oxalato ligands, and the endo-cyclic nitrogen atoms, from two n-ampy ligands, buildingdistorted octahedral surroundings. The aromatic bases are bound to the metal atom in cis (1-6) or trans (7-9)positions. Magnetic susceptibility measurements in the temperature range of 2-300 K show the occurrence ofantiferromagnetic intrachain interactions except for the compound 3 in which a weak ferromagnetic coupling isobserved. Compound 7 shows spontaneous magnetization below 8 K, which corresponds to the presence of spincanted antiferromagnetism.