Further study of the linear trinickel(II) complex of dipyridylamide
Further study of the linear trinickel(II) complex of dipyridylamide
复制标题
DOI：
10.1021/ic990006t
复制
发表时间：
1999-05-31
影响因子：
4.6
通讯作者：
Wang, XP
中科院分区：
文献类型：
--
作者：
Clérac, R;Cotton, FA;Wang, XP
标题化合物Ni-3(Dpa)(4)Cl-2(dpa=二(2-吡啶基)氨基阴离子)于30年前首次报道，结构鉴定于1991年，以两种新的晶型Ni-3(Dpa)(4)Cl-2得到。2CH(2)Cl(2)(四方晶格，空间群I(4)，a=27.3046(7)Angstrom，c=12.2452(2)Angstrom，Z=8)和Ni-3(Dpa)(4)Cl-2。四氢呋喃(正交，PCcn空间群，a=12.673(1)Angstrom，b=14.138(3)Angstrom，c=23.890(2)Angstrom，Z=4)。对它们的结构进行了研究，其中一种化合物的磁性质测定范围为2~300K，并记录了质子核磁共振谱。这些数据可以得出以下结论：(1)分子结构在三种晶型中是不变的，并具有对称的镍原子链；(2)末端金属原子都有两个未配对的电子，而中心原子是典型的抗磁性方形平面Ni-II络合物；(3)两个末端镍(II)离子的磁矩表现为反铁磁耦合，2J=-108 cm(-1)；(4)Ni-3链在溶液中保持对称。
The title compound, Ni-3(dpa)(4)Cl-2 (dpa = di(2-pyridyl)amido anion), first reported 30 years ago, structurally characterized in 1991, has been obtained in two new crystal forms, Ni-3(dpa)(4)Cl-2. 2CH(2)Cl(2) (tetragonal, space group I (4) over bar, with a = 27.3046(7) Angstrom, c = 12.2452(2) Angstrom, Z = 8) and Ni-3(dpa)(4)Cl-2. THF (orthorhombic, space group Pccn, with a = 12.673(1) Angstrom, b = 14.138(3) Angstrom, c = 23.890(2) Angstrom, Z = 4). They have been examined structurally, and the magnetic properties of one of them determined from, 2 to 300 K. Also the proton NMR spectrum has been recorded. These data allow the following conclusions to be drawn: (1) the molecular structure is invariant in the three crystalline forms and has a symmetrical chain of nickel atoms, (2) the terminal metal atoms each have two unpaired electrons, while the central one is typical of diamagnetic square-planar Ni-II complexes, (3) the magnetic moments of the two terminal nickel(II) ions display antiferromagnetic coupling, with 2J = -108 cm(-1), and (4) the Ni-3 chain remains symmetrical in solution.