Exploring the RIDEr ligation at supported PORPHyrins using a combined theory and experiment atomic-scale approach_RIDEPORPH

金属卟啉是一类干扰多种生物过程的功能分子。它们存在于血红蛋白中，并参与呼吸道气体的运输。使用扫描隧道显微镜，德国慕尼黑理工大学的实验团队最近发现，在吸附状态下，卟啉大循环采用了特征的马鞍形变形。此外，在探索卟啉对气体物种的响应时，研究表明，存在两个吸附CO的位置，这两个位置可以通过与里昂理论团队的从头计算相比较来确定。事实上，羰基加合物位于鞍座的侧面，类似于骑手的腿的位置。马鞍形构象可能代表了这一情景中的一个关键因素，本项目将详细检验这一假设。一个需要通过系统方法研究的原始问题是，这种史无前例的结合模式是否可以类似地适用于相关环境。里昂和慕尼黑团队确定了四个组成化学参数，这些参数可以单独改变，以区分它们对骑手连接模式的存在或不存在的内在影响：(I)卟啉大环的构象，(Ii)气态加合物的性质，(Iii)金属中心的类型和(Iv)底物的反应性。这一研究战略依赖于慕尼黑的分子成像和操纵实验，并借助里昂的原子计算进行了解释。

Metalloporphyrins represent a class of functional molecules that interfere in numerous biological processes. They are present in hemoglobin and mediate the transport of respiratory gases. Using scanning tunneling microscopy, the experimental team at TU Munich recently showed that in the adsorbed state the porphyrin macrocycle adopts a characteristic saddle-shape deformation. Moreover, exploring the porphyrin's response to gaseous species, the studies demonstrate that there exist two adsorption sites for CO, which could be identified by the comparison with ab-initio calculations from the theoretical team at Lyon. Indeed, the carbonyl adducts are located sideways at the saddle, similar to the positioning of the legs of a rider. The saddle-shape conformation presumably represents a key factor in this scenario, which hypothesis the present project will examine in detail. A primordial question to be investigated by a systematic approach is whether this unprecedented bonding mode can be similarly invoked for related environments. The Lyon and Munich teams identified four constituent chemical parameters that can be individually varied to differentiate their intrinsic effect on the existence or non-existence of the rider ligation mode: (i) the conformation of the porphyrin macrocycle, (ii) the nature of the gaseous adduct, (iii) the type of the metal center and (iv) the reactivity of the substrate. The research strategy relies on molecular imaging and manipulation experiments at Munich interpreted with the help of atomistic calculations in Lyon.