화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.369, 47-62, 2001
Solid dimorphism of tetra-arylcyclobutadienecobalt derivatives bearing long aliphatic lateral groups
A new series of disk-like cyclobutadienecobalt derivatives symmetrically substituted by lateral alkoxy groups with different chain lengths (-O(CH2)(n)CH3, n=5, 6, 8, and 12) were prepared and their thermal phase transition behavior was studied in detail by optical measurements using crossed polarizers and differential scanning calorimetry (DSC). These cyclobutadienecobalt derivatives revealed dimorphism: two types of crystals K-1 and K-2 (crystals with lower and higher m.p., respectively) were observed. The thermal transition mechanisms (melt-mediated crystallization) could be clearly observed. The melting points of both K-1 and K-2 became lower as the number of the carbon atoms in the alkoxy chain increased.