Influence of dehydration on the electron spin resonance in the Cu$_3$[W(CN)$_8$]$_2$(pyrimidine)$_2$ $\cdot$ 8Н$_2$О molecular magnet

The influence of dehydration on the electron spin resonance spectra in the Cu$_3$[W(CN)$_8$]$_2$(pyrimidine)$_2$ $\cdot$ 8Н$_2$О molecular magnet has been found. It has been established that two ferromagnetic phases with the Curie temperatures of $\sim$12–17 and $\sim$50 K, which correspond to two different lines of the ferromagnetic resonance, are present in crystals. Dehydration leads to increasing the Curie temperature of the low-temperature phase from 12 to 17 K and to varying the temperature dependences of the spectrum parameters of the high-temperature phase (the resonant field and the width line).