机构地区:[1]河北师范大学分析测试中心,化学与材料科学学院,石家庄050024 [2]河北省特种设备监督检验研究院,石家庄050000 [3]邯郸学院,化学化工与材料学院,河北省杂环化合物重点实验室,河北邯郸056005
出 处:《物理化学学报》2023年第1期56-66,共11页Acta Physico-Chimica Sinica
基 金:supported by the National Natural Science Foundation of China(22273015,21803016)。
摘 要:采用室温溶液挥发法合成了五种结构新颖的镧系配合物,其结构通式为[Ln(2,4-DFBA)3(phen)]2(Ln=Sm 1,Eu2,Er 3,2,4-DFBA为2,4二氟苯甲酸的简写,phen为1,10-菲啰啉的简写),[Ln(2-Cl-6-FBA)2(terpy)(NO3)(H2O)]2(Ln=Tb4,Dy 5,2-Cl-6-FBA为2-氯-6-氟苯甲酸的简写,terpy为2,2’:6’2’’-三联吡啶的简写)。五个配合物可以分为两个系列,使用不同的镧系离子作为中心离子。通过X射线单晶分析,5种配合物均属于单斜晶系,空间群为P21/n。配合物1,2和配合物3虽然具有相同的分子通式,但配位方式明显不同,形成了前者为9配位的松饼型,后者是8配位的双帽三棱柱几何构型。二维面状超分子结构的形成方式也明显不同,区别在于配合物1和2通过微弱的π-π堆积作用形成。配合物4和5是同构的,结构中引入了硝酸根离子较为有趣,通过C―H···F氢键和π-π堆积作用形成二维面状超分子结构。在299.25–1073.15K温度下对配合物1–5通过热重-微分热重-差示扫描量热/红外光谱(TG-DTG-DSC/FTIR)联用技术进行热分解机理的研究。测定了配合物1,2,4,5的固体荧光,特征过渡峰位于^(4)G_(5/2)→^(6)H_(5/2),^(4)G_(5/2)→^(6)H_(7/2),^(4)G_(5/2)→^(6)H_(9/2)(1),^(5)D_(0)→^(7)F_(0),^(5)D_(0)→^(7)F_(1),^(5)D_(0)→^(7)F_(2),^(5)D_(0)→^(7)F_(3),^(5)D_(0)→^(7)F_(4)(2),^(5)D_(4)→^(7)F_(6),^(5)D_(4)→^(7)F_(5),^(5)D_(4)→^(7)F_(4),^(5)D_(4)→^(7)F_(3)(4),和^(4)F_(9/2)→^(6)H_(15/2),^(4)F_(9/2)→^(6)H_(13/2)(5),均表现出镧系离子的特征过渡峰。此外,还对配合物2和4进行了荧光寿命的研究,其荧光衰减时间分别为1.288和0.648 ms。In this study,new lanthanide complexes were synthesized via the volatilization method in solution at room temperature.The general molecular formulas for the lanthanide complexes are as follows:[Ln(2,4-DFBA)3(phen)]2(Ln=Sm 1,Eu 2,and Er 3;2,4-DFBA=2,4-difluorobenzoate;and phen=1,10-phenanthroline),as well as[Ln(2-Cl-6-FBA)2(terpy)(NO3)(H2O)]2(Ln=Tb 4 and Dy 5;2-Cl-6-FBA=2-chloro-6-fluorobenzoate;and terpy=2,2’:6’2’’-tripyridine).Based on single-crystal Xray analysis,the five complexes exhibited a monoclinic crystal structure belonging to the space group P21/n.Even though complexes 1,2(Ⅰ),and 3(Ⅱ)share a general molecular formula,their coordination modes were different.For example,complexes 1 and 2 formed a muffin-like structure with nine coordinated atoms,while complex 3 formed a double hat triangular geometry with eight coordinated atoms.The two-dimensional(2D)polyhedral structures of complexes 1 and 2 were formed via weakπ-πstacking interactions,whereas complex 3 exhibited a 2D faceted supramolecular structure through C―H···F hydrogen bonds.Complexes 4 and 5 were isostructural,with the presence of nitrate ions in their structure.This occurred through the C―H···F hydrogen bonds andπ-πstacking of the molecules to form a faceted supramolecular crystal structure.A series of characterizations,such as elemental analysis,infrared and Raman spectroscopy,as well as powder X-ray diffraction,were performed on the five complexes.Thermogravimetry-derivative thermogravimetry-differential scanning calorimetry were performed between 299.25 and 1073.15 K to investigate the mechanism for the thermal decomposition of complexes 1–5.The analysis of the escaping gas stacking maps of the five complexes using thermogravimetric and 3D infrared coupling techniques further confirmed the correctness of the thermal decomposition mechanism of each complex.The results obtained revealed that similar structured complexes follow a similar thermal decomposition mechanism,and the end solid products for all complexes wer
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...