One-dimensional (1D) spin-1 (S = 1) chain of organic radicals with low local magnetic anisotropy may provide a better understanding of the low-dimensional magnetism. We report solid-state studies, including single crystal X-ray crystallography, of air-stable tetraazacyclophane diradical dication salt 1(2.2+)center dot 2[Al(OC(CF3)(2)CH3)(4)](-) with a triplet ground state (Delta E-ST approximate to 0.5 kcal mol(-1)). The magnetic behavior for 1(2.2+) at low temperature is best modeled by 1D spin S = 1 Heisenberg chain with intrachain antiferromagnetic coupling of J'/k = -5.4 K, which is associated with the interaryl C center dot center dot center dot C contacts, including pi-pi interactions. Zero-field splitting value, vertical bar D/hcl approximate to 5.6 x 10(-3) cm(-1), for 1(2.2+) is rather small; thus, the 1D chains are characterized by the high degree of isotropicity vertical bar D/2J'vertical bar approximate to 7.5 x 10(-4). The diradical dication salt possesses extraordinary stability with onset of decomposition at temperature of about 180 degrees C (similar to 450 K), based on thermogravimetric analysis and EPR spectroscopy.