Dipicolylamine Complexes of Copper(II): Two Different Coordination Geometries in the Same Unit Cell of Cu(Dipica)2(BF4)2
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- 作者：Mallayan Palaniandavar ; Raymond J. Butcher ; and Anthony W. Addison
- 刊名：Inorganic Chemistry
- 出版年：1996
- 出版时间：January 17, 1996
- 年：1996
- 卷：35
- 期：2
- 页码：467 - 471
- 全文大小：150K
- 年卷期：v.35,no.2(January 17, 1996)
- ISSN：1520-510X
文摘
Bright blueCu(Dipica)2(BF4)2crystallizes in the monoclinic space groupP21/n, with unit cell parametersa =23.406(6) Å, b = 9.338(2) Å, c =25.573(7) Å, 
= 95.39(2)
, and Z = 8.The structure was solved by conventionalPatterson and Fourier methods. The R andRw values for 5282 observed reflections were7.06% and 9.10%respectively. Two structurally different complex cations arepresent in the same unit cell, one hexacoordinateand the other pentacoordinate. In the hexacoordinate cation, thetwo tridentate bis(2'-picolyl)amine ligands aretrans-facially coordinated with two pyridine nitrogens andthe two secondary amine nitrogens situated on fourpositions in a plane [Cu-Npyr = 2.189(6),2.146(6) Å; Cu-Nsat = 2.207(6),2.201(5) Å]. The remaining twopyridine nitrogens constitute the axis [Cu-Npyr =2.035(5), 2.038(5) Å] in an equatoriallyexpandedpseudooctahedral geometry. The pentacoordinate cation possesses asquare-pyramidal configuration, the twosecondary nitrogens being mutually cis, with one Dipicaequatorially tridentate [Cu-Npyr = 2.044(5),2.027(5)Å, Cu-Nsat = 1.995(5) Å]. The other Dipicafunctions as a bidentate ligand, with one of the pyridinenitrogensoccupying the equator [Cu-Npyr = 1.986(5) Å]and the aliphatic nitrogen defining the axial copperposition[Cu-Nsat = 2.344(5) Å]. Its secondpyridine is uncoordinated but hydrogen-bonded to the coordinated NHofthe other ligand. Solution properties offer no clear distinctionbetween the two cation stereochemistries. Theternary chelates [Cu(Dipica)(Acac)]ClO4and [Cu(Dipica)(Bipy)](ClO4)2are also described.
= 95.39(2), and Z = 8.The structure was solved by conventionalPatterson and Fourier methods. The R andRw values for 5282 observed reflections were7.06% and 9.10%respectively. Two structurally different complex cations arepresent in the same unit cell, one hexacoordinateand the other pentacoordinate. In the hexacoordinate cation, thetwo tridentate bis(2'-picolyl)amine ligands aretrans-facially coordinated with two pyridine nitrogens andthe two secondary amine nitrogens situated on fourpositions in a plane [Cu-Npyr = 2.189(6),2.146(6) Å; Cu-Nsat = 2.207(6),2.201(5) Å]. The remaining twopyridine nitrogens constitute the axis [Cu-Npyr =2.035(5), 2.038(5) Å] in an equatoriallyexpandedpseudooctahedral geometry. The pentacoordinate cation possesses asquare-pyramidal configuration, the twosecondary nitrogens being mutually cis, with one Dipicaequatorially tridentate [Cu-Npyr = 2.044(5),2.027(5)Å, Cu-Nsat = 1.995(5) Å]. The other Dipicafunctions as a bidentate ligand, with one of the pyridinenitrogensoccupying the equator [Cu-Npyr = 1.986(5) Å]and the aliphatic nitrogen defining the axial copperposition[Cu-Nsat = 2.344(5) Å]. Its secondpyridine is uncoordinated but hydrogen-bonded to the coordinated NHofthe other ligand. Solution properties offer no clear distinctionbetween the two cation stereochemistries. Theternary chelates [Cu(Dipica)(Acac)]ClO4and [Cu(Dipica)(Bipy)](ClO4)2are also described.