稀土噻吩甲酰三氯丙酮络合物的傅里叶红外光谱

在100—4000 cm^-1范围内,研究了十四个稀土三螯合噻吩甲酰三氟丙酮二水络合物RE(TTA)₃·2H₂O的傅里叶红外光谱。对照前人工作对络合物的谱带作了指认。观察到六个RE—O振动,两个在中红外区(456—475)和489—508cm^-1),四个在远红外区(173—190、213—228、362—374和396—408cm^-1)。中红外区456和489cm^-1附近的谱带随稀土原子序数的变化呈“四分组”效应。羰基及不饱和碳碳键吸收峰都比噻吩甲酰三氟丙酮低60多个波数。

FTIR STUDY OF RARE EARTH TRIS(4,4,4-TRIFLUORO-1-(2-THIENYL)-1,3-BUTANEDIONE)DIHYDRATES

The FTIR spectra of fourteen rare earth tris (4,4,4-trifluoro-1-(2-thie-nyl)-1, 3-butanedione ) dihydrates in the 100-4000 cm^-1 range have beenstudied and the assignment of peaks in the far and middle infrared regionhas been discussed. Six RE--O absorption bands were observed, two ofwhich are in the mid--infrared region, namely 489--508 cm^-1 for the asym-metrical stretch and 456--475^-1cm for the symmetrical stretch. Four bandsare in the far infrared region, three of them are assigned to the metal-che-late oxygen bonds, while the fourth band results from the coordinationwith the water molecule. The frequencies of the bands near 456-489^-1cm change periodically with atomic number, showing the "tetrad effect", whichis characteristic of lanthanides. The absorption peak due to the carbonyl groupand that due to the C=C bond are lowered by about 60cm^-1 respectivelyin comparison with the free HTTA. This is an evidence of conjugation inthe metal chelate rings.