Electron Paramagnetic Resonance Analysis of Damage Center in a Gamma-Irradiated Bicyclo[2.2.1]Hept-5-Ene-2,3-Dicarboxylic Anhydride Single Crystal
Journal of Spectroscopy, cilt.2026, sa.1, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 2026 Sayı: 1
- Basım Tarihi: 2026
- Doi Numarası: 10.1155/jspe/7262789
- Dergi Adı: Journal of Spectroscopy
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC, Directory of Open Access Journals, Technology Collection (ProQuest)
- Anahtar Kelimeler: bicyclo[2.2.1]hept-5-ene-23-dicarboxylic anhydride, EPR, hyperfine coupling constant, radiation damage center, spectroscopic splitting factor
- Ankara Üniversitesi Adresli: Evet
Özet
Gamma irradiation effects on single crystals of bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride were investigated by angular-dependent single-crystal Electron Paramagnetic Resonance (EPR) spectroscopy. Irradiation with a 60Co source resulted in the formation of a stable carbon-centered radical, whose magnetic properties were characterized through systematic rotation of the crystal. The principal components of the anisotropic g-tensor and hyperfine interaction tensors were determined from orientation-dependent spectra. Two distinct hyperfine splitting patterns (β and γ) were resolved, indicating interactions of the unpaired electron with different sets of −C2H2 protons within the constrained molecular framework. The orthorhombic crystal symmetry enabled reliable correlation between tensor principal values and crystallographic axes, strengthening the structural assignment of the radical center. The results demonstrate that the rigid norbornene-bridged framework significantly influences spin localization, tensor anisotropy, and radical stability. Overall, this study highlights the combined role of molecular rigidity and crystal symmetry in governing radiation-induced defect formation and establishes a clear structure–property relationship in organic anhydride crystals.