Syntheses, optical and intramolecular magnetic properties of mono- and di-radicals based on nitronyl-nitroxide and oxoverdazyl groups appended to 2,6-bispyrazolylpyridine cores
作者:Pramiti Hui、Khaja Md. Arif、Rajadurai Chandrasekar
DOI:10.1039/c2ob06875c
日期:——
series of nitronyl-nitroxide (NN), oxoverdazyl (OVZ) based mono-, and bi-radicals attached to 4-phenyl-2,6-bispyrazolylpyridine coupling unit, their optical, electron spin resonance (ESR) spectroscopic studies and computational analysis. The ESR studies revealed that the axial zero-field splitting (zfs) parameter of the NN biradical (|D/hc| = 0.00719 cm−1) is larger than the OVZ biradical (|D/hc| =
本文介绍了一系列硝酰基-硝基氧(NN),氧杂二氮基(OVZ)的合成基团,该基团与4-苯基-2,6-双吡唑基吡啶偶联单元相连,具有光学,电子自旋共振(ESR) )的光谱学研究和计算分析。ESR研究表明,NN双自由基(| D / hc | = 0.00719 cm -1)的轴向零场分裂(zfs)参数大于OVZ双自由基(| D / hc | = 0.00601 cm -1)。此外,两个双自由基均显示出禁止的半场跃迁(ΔM s =±2; g av〜4.01)在170 K时证明了它们的三重态。对两个双自由基的低温ESR测量显示,居里磁行为的ΔM s =±2信号强度(χEPR)降至4.2K。自旋-自旋交换耦合(Ĵ二者NN和OVZ基于双自由基的)表明,两种双自由基的基态自旋多重可能是三重峰(小号= 1)或它几乎与简并的单线态-三线态Ĵ NN » Ĵ OVZ。