Rosales-Martínez Carmen, Matilla-Hernádez Antonio, Choquesillo-Lazarte Duane, Frontera Antonio, Castiñeiras Alfonso, Niclós-Gutiérrez Juan
Department of Inorganic Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain.
Laboratorio de Estudios Cristalográficos, IACT, CSIC-Universidad de Granada, Avda. de las Palmeras 4, Armilla, 18100 Granada, Spain.
Molecules. 2023 Aug 2;28(15):5830. doi: 10.3390/molecules28155830.
Considering that Cu(tda) chelate (tda: dithioacetate) is a receptor for adenine and related 6-aminopurines, this study reports on the synthesis, molecular and crystal structures, thermal stability, spectral properties and DFT calculations related to [Cu(tda)(9heade)(HO)]·2HO () [9heade: N9-(2-hydroxyethyl)adenine]. Concerning the molecular recognition of (metal chelate)-(adenine synthetic nucleoside), represents an unprecedented metal binding pattern (MBP) for 9heade. However, unprecedentedly, the Cu(tda)-9heade molecular recognition in is essentially featured in the Cu-N1(9heade) bond, without any N6-H⋯O(carboxyl tda) interligand interaction. Nevertheless, N1 being the most basic donor for N9-substituted adenines, this Cu-N1 bond is now assisted by an O2-water-mediated interaction (N6-H⋯O2 and O2⋯Cu weak contact). Also, in the crystal packing, the O-H(ol) of 9heade interacts with its own adenine moiety as a result of an O3-water-mediated interaction (O(ol)-H⋯O3 plus O3-H36⋯π(adenine moiety)). Both water-mediated interactions seem to be responsible for serious alterations in the physical properties of crystalline or grounded samples. Density functional theory calculations were used to evaluate the interactions energetically. Moreover, the quantum theory of atoms-in-molecules (QTAIM), in combination with the noncovalent interaction plot (NCIPlot), was used to analyze the interactions and rationalize the existence and relative importance of hydrogen bonding, chalcogen bonding and π-stacking interactions. The novelty of this work resides in the discovery of a novel binding mode for N9-(2-hydroxyethyl)adenine. Moreover, the investigation of the important role of water in the solid state of is also relevant, along with the chalcogen bonding interactions demonstrated by the density functional theory (DFT) study.
鉴于Cu(tda)螯合物（tda：二硫代乙酸酯）是腺嘌呤及相关6-氨基嘌呤的受体，本研究报告了与[Cu(tda)(9heade)(HO)]·2HO () [9heade：N9-(2-羟乙基)腺嘌呤]相关的合成、分子和晶体结构、热稳定性、光谱性质及密度泛函理论计算。关于（金属螯合物）-（腺嘌呤合成核苷）的分子识别， 代表了9heade前所未有的金属结合模式（MBP）。然而，前所未有的是， 中Cu(tda)-9heade的分子识别主要以Cu-N1(9heade)键为特征，没有任何N6-H⋯O（羧基tda）配体间相互作用。尽管如此，N1是N9-取代腺嘌呤最基本的供体，现在这种Cu-N1键由O2-水介导的相互作用（N6-H⋯O2和O2⋯Cu弱接触）辅助。此外，在晶体堆积中，9heade的O-H(ol)由于O3-水介导的相互作用（O(ol)-H⋯O3加上O3-H36⋯π（腺嘌呤部分））与其自身的腺嘌呤部分相互作用。这两种水介导的相互作用似乎都导致了晶体或研磨样品物理性质的严重改变。密度泛函理论计算用于从能量上评估相互作用。此外，分子中的原子量子理论（QTAIM）与非共价相互作用图（NCIPlot）相结合，用于分析相互作用并合理化氢键、硫族键和π堆积相互作用的存在及相对重要性。这项工作的新颖之处在于发现了N9-(2-羟乙基)腺嘌呤的一种新型结合模式。此外，研究水在 固态中的重要作用以及密度泛函理论（DFT）研究所证明的硫族键相互作用也具有重要意义。
