Variable temperature magnetic susceptibility data were measured for powder samples of 1-RE•0.5MeCN (RE = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) from 1.8 to 300 K with applied field of 1000 Oe (Figure ). The measured MT values at room temperature are consistent with the values calculated for RE 3+ complexes (Table ). Compounds 1-RE•0.5MeCN (RE = Tb, Dy, Ho, Er, Tm and Yb) exhibit a marked decrease in MT upon cooling below 50 K, which can be attributed to thermal depopulation of energy levels due to the CF splitting. The linear MT profile evident for 1-Eu•0.5MeCN and 1-Sm•0.5MeCN across the measured temperature range is due to temperature independent paramagnetism (TIP).