Versatile coordination architectures of products generated by the in situ reaction of a doubly bis(2-pyridyl)pyrazolate bridged dinuclear copper(ii) complex with tetracyanoethylene
Versatile coordination architectures of products generated by the in situ reaction of a doubly bis(2-pyridyl)pyrazolate bridged dinuclear copper(ii) complex with tetracyanoethylene
复制标题
双双(2-吡啶基)吡唑酯桥联双核铜(ii)络合物与四氰乙烯原位反应生成的产物的多功能配位结构
DOI：
10.1039/c9ce00036d
复制
发表时间：
2019
期刊：
影响因子：
3.1
通讯作者：
Kawata Satoshi
中科院分区：
文献类型：
--
作者：
Ishikawa Ryuta;Ueno Shunya;Hamatake Yumi;Horii Yoji;Miyazaki Yuji;Nakano Motohiro;Noda Takeshi;Uematsu Mikoto;Kawata Satoshi
双双金属的反应（2-吡啶基）吡唑（bpypz−）桥联双核铜（II）配合物[Cu 2（bpypz）2]2+与中性四氰基乙烯（TCNE）形成[Cu 4（bpypz）4（TCVA）2]·2 TCVA（1）（在四氢呋喃（THF）中）、顺式-[Cu 2（bpypz）2（DCNM）2]（2）（在MeOH中）和反式-[Cu 2（bpypz）2（DCNE）2]（3）（在EtOH中），其中TCVA− = 1，2，2-tricyanoethenolate，DCNM− = 2，2-dicyano-1-methoxyethenolate，DCNE− = 2，2-dicyano-1-ethoxyethenolate。1-3中的配位体TCVA-、DCME-和DCNE-在不同溶剂中的反应过程中原位形成，并且通过红外光谱、单晶X射线衍射和元素分析来确认配位体。1-3的单晶X射线结构表明，每个铜（II）中心是五坐标的近似正方形金字塔几何形状。1是一个离散的二聚体的二聚体类型的四核配合物，铜（II）中心由两个trans-μ2-N，O-TCVA−桥接。2和3是分立的双核配合物。在2中，两个顶部单齿N-配位的DCNM−分子以顺式方式彼此取向，因此采用顺式正交构型。每个铜（II）中心与相邻铜（II）双核单元的顶部配位DCNM-分子的O原子之间存在弱相互作用，导致伪一维梯状配位聚合物排列。在3中，两个顶部单齿N-配位的DCNE−分子以相互反式的方式穿过[Cu 2（bpypz）2]2+的基面，从而采用反正交构型。连续波X-波段电子顺磁共振光谱测量细磨多晶样品1-3证实了热人口减少S = 1三重态所产生的反铁磁耦合两个S = 1/2自旋与正交g值。变温直流磁化率测量值为1-3，表明双bpypz-桥连铜（II）中心存在显著的反铁磁耦合（由各向同性自旋哈密顿量H = − 2 JS 1·S2量化，对于两个铜（II）中心：1、2和3分别为J = −217.7、−210.3和−188.5 cm−1）。
The reaction of a doubly bis(2-pyridyl)pyrazolate (bpypz−) bridged dinuclear copper(II) complex, [Cu2(bpypz)2]2+, with neutral tetracyanoethylene (TCNE) results in the formation of [Cu4(bpypz)4(TCVA)2]·2TCVA (1) in tetrahydrofuran (THF), syn-[Cu2(bpypz)2(DCNM)2] (2) in MeOH, and anti-[Cu2(bpypz)2(DCNE)2] (3) in EtOH, where TCVA− = 1,2,2-tricyanoethenolate, DCNM− = 2,2-dicyano-1-methoxyethenolate, and DCNE− = 2,2-dicyano-1-ethoxyethenolate. The ligands TCVA−, DCME−, and DCNE− in 1–3 were formed in situ during the reaction in different solvents, and the ligands were confirmed through infrared spectroscopy, single-crystal X-ray diffraction, and elemental analyses. The single-crystal X-ray structures of 1–3 show that each copper(II) centre is five-coordinate in an approximately square pyramidal geometry. 1 is a discrete dimer-of-dimers type tetranuclear complex with the copper(II) centres bridged by two trans-μ2-N,O-TCVA−. 2 and 3 are discrete dinuclear complexes. In 2, two apically monodentate N-coordinated DCNM− molecules are oriented in a cis manner to one another, consequently adopting a syn-orthogonal configuration. A weak interaction exists between each copper(II) centres and the O atoms of the apically coordinated DCNM− molecules of the neighbouring copper(II) dinuclear units, resulting in a pseudo one-dimensional ladder-like coordination polymer arrangement. In 3, two apically monodentate N-coordinated DCNE− molecules are oriented in a mutually trans manner across the basal plane of [Cu2(bpypz)2]2+, thereby adopting an anti-orthogonal configuration. Continuous wave X-band electron paramagnetic resonance spectral measurements on finely ground polycrystalline samples of 1–3 confirm a thermally depopulated S = 1 triplet state arising from antiferromagnetically coupled two S = 1/2 spins with orthorhombic g values. Variable-temperature dc magnetic susceptibility measurements of 1–3 indicate significant antiferromagnetic coupling (quantified by the isotropic spin Hamiltonian, H = −2JS1·S2, for the two copper(II) centres: J = −217.7, −210.3, and −188.5 cm−1 for 1, 2 and 3, respectively) for the doubly bpypz− bridged copper(II) centres.