Abstract A new oligo(ethylene glycol)-thioacetyl substituted theophylline (THEO) has been synthesized and used to form self-assembled monolayers (SAMs) on different gold substrates. The THEO-SAMs formed are compact and passivate the gold surface in an important extension. The thioacetyl group can be deprotected to release the mercapto-derivative that gives place to Au-S bond either in the absence or in the presence of base. Evidences that the THEO molecules bind to gold as thiolates are given by the behavior of the reductive desorption process of the SAM as a function of solution pH. However, some of the molecules can suffer breakage in the C-S position releasing thioacetic acid and the fragment oligo(ethylene glycol)-theophylline that can't bind to gold. The thioacetic acid generated at the gold surface can be catalytically decomposed to acetyl and atomic sulfur. The later can be bound to gold as it has been demonstrated by electrochemical as well as by XPS techniques. The resulting THEO-SAM has been structurally characterized by IRRAS. Comparison of the IRRAS with the spectrum of the bulk molecules allows us to conclude about some degree of organization of the THEO chains upon SAM formation. The results of this study can be translated to a gold nanomaterial conjugate to be assayed in studies of theophylline derivatives drug delivery in living systems.

中文翻译：

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低聚（乙二醇）-硫代乙酰基取代茶碱（THEO）在金基材上的自组装过程研究

摘要 合成了一种新的低聚（乙二醇）-硫代乙酰基取代的茶碱（THEO），并用于在不同的金基材上形成自组装单分子层（SAMs）。形成的 THEO-SAM 是致密的，并且在重要的延伸中钝化了金表面。硫代乙酰基可以脱保护以释放巯基衍生物，在碱不存在或存在的情况下，该巯基衍生物让位给 Au-S 键。THEO 分子作为硫醇盐与金结合的证据是由 SAM 的还原解吸过程的行为作为溶液 pH 值的函数给出的。然而，一些分子会在 CS 位置发生断裂，释放出硫代乙酸和不能与金结合的低聚（乙二醇）-茶碱片段。在金表面产生的硫代乙酸可以催化分解为乙酰基和原子硫。后者可以与金结合，正如电化学和 XPS 技术所证明的那样。由此产生的 THEO-SAM 已通过 IRRAS 进行结构表征。将 IRRAS 与本体分子的光谱进行比较，我们可以得出关于 SAM 形成时 THEO 链的某种程度组织的结论。这项研究的结果可以转化为金纳米材料偶联物，以用于生命系统中茶碱衍生物药物递送的研究。将 IRRAS 与本体分子的光谱进行比较，我们可以得出关于 SAM 形成时 THEO 链的某种程度组织的结论。这项研究的结果可以转化为金纳米材料偶联物，以用于生命系统中茶碱衍生物药物递送的研究。将 IRRAS 与本体分子的光谱进行比较，我们可以得出关于 SAM 形成时 THEO 链的某种程度组织的结论。这项研究的结果可以转化为金纳米材料偶联物，以用于生命系统中茶碱衍生物药物递送的研究。