Tritium labelled 2,5-diphenyloxazole ([3H]-PPO, 1) and 4-hydroxymethyl-2,5-diphenyloxazole ([3H]-4-HOCH2-PPO, 2) have been prepared using a one-step metal catalysed isotope exchange procedure. Compound 1 was then encapsulated into a solâgel glass via the polymerisation of tetraethyl orthosilicate (TEOS). Compound 2 was first reacted with 3-isocyanatopropyltriethoxysilane (3-ICPS) to form a functionalised silicon alkoxide precursor which has a urethane linkage ([3H]-urethane 4), and subsequently copolymerised with TEOS to form covalently bonded solâgel glasses. The performance of the two glasses was differentiated on the basis of radioactivity leaching tests. In the case of the covalently bound version virtually no leaching occurred, thereby making it an attractive candidate for further applications.
使用一步
金属催化同位素交换程序合成了氚标记的2,5-二苯基
噁唑([3H]-
PPO,1)和4-羟甲基-2,5-二苯基
噁唑([3H]-4-HOCH2-PPO,2)。随后,将化合物1通过四乙氧基
硅烷(TEOS)的聚合包封到溶胶-凝胶
玻璃中。化合物2首先与3-异
氰酸丙基三乙氧基
硅烷(3-ICPS)反应,形成具有
尿烷连接的功能化
硅醇前体([3H]-
尿烷4),然后与TEOS共聚合,形成共价键合的溶胶-凝胶
玻璃。两个
玻璃的性能通过放射性浸出测试进行了区分。在共价结合的版本中几乎没有浸出发生,因此使其成为进一步应用的一个有吸引力的候选者。