摘要
在弱酸性介质中,氯化镍和柠檬酸铵反应可得到镍水合离子与二聚柠檬酸镍配离子的加合配合物(NH4)[Ni(H2O)6][Ni(Hcit)(H2O)2]4·10H2O1。该配合物的晶体属三斜晶系,空间群为P1,晶胞参数:a=9.7273(9),b=12.034(2),c=13.348(2),α=63.54(2),β=88.45(1),γ=86.28(1)°,V=1395.9(3)3,Z=1,配合物的阳离子为两个铵离子和一个六水合镍离子,阴离子由两个二聚柠檬酸镍[Ni(Hcit)(H2O)2]2-2组成。在不对称的配阴离子中,两个柠檬酸分别以羟基、α-羧基和一个β-羧基同第一个镍配位,剩下的β-羧基作为桥基同另一个镍配位形成二聚体。
? The complex (NH 4) 2[Ni(H 2O) 6][Ni(Hcit)(H 2O) 2] 4·10H 2O1 was separated from the reaction of nickel chloride and ammonium citrate at pH 3. Its crystal structure was determined by Xray methods . Compound 1 is triclinic, space group P1, with a=9.7273(9), b=12.034(2), c=13.348(2), α=63.54(2), β=88.45(1), γ=86.28(1)°, V=1395.9(3) 3, Z=1, R=0.0729, R W=0.0798 for 2760 observed reflections. The structure consists of ammonium cation, hexahydrate nickel(Ⅱ) cation and two centrosymmetric tetradentate citrato nickel(Ⅱ) dimeres, [Ni(Hcit)(H 2O) 2] 2- 2. The average principal NiO dimensions are: NiO(hydroxy), 2.070(8), NiO(αcarboxy), 2.041(8), NiO(βcarboxy), 2.055(8), NiO(water), 2.053(8). It is deduced that the complex is formed by the coprecipitation of dimeric citrato nickel(Ⅱ) anion and hexahydrate nicke(Ⅱ), in which the later is produced from the decomposition of dimeric citrato nickel(Ⅱ) or dicitrato nickel(Ⅱ) anion.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
1997年第4期385-389,共5页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金
关键词
柠檬酸镍
镍
配合物
晶体结构
\ \ \ citric acid nickel(Ⅱ) complex\ \ \ citrate method electroplatingcrystal structure