In the past decade, many gas-phase spectroscopic investigations have focused on the understanding of the nature of weak interactions in model systems. Despite the fact that non-covalent interactions play a key role in several biological and technological processes, their characterization and interpretation are still far from being satisfactory. In this connection, integrated experimental and computational investigations can play an invaluable role. Indeed, a number of different issues relevant to unraveling the properties of bulk or solvated systems can be addressed from experimental investigations on molecular complexes. Focusing on the interaction of biological model systems with solvent molecules (e.g., water), since the hydration of the biomolecules controls their structure and mechanism of action, the study of the molecular properties of hydrated systems containing a limited number of water molecules (microsolvation) is the basis for understanding the solvation process and how structure and reactivity vary from gas phase to solution. Although hydrogen bonding is probably the most widespread interaction in nature, other emerging classes, such as halogen, chalcogen and pnicogen interactions, have attracted much attention because of the role they play in different fields. Their understanding requires, first of all, the characterization of the directionality, strength, and nature of such interactions as well as a comprehensive analysis of their competition with other non-covalent bonds. In this review, it is shown how state-of-the-art quantum-chemical computations combined with rotational spectroscopy allow for fully characterizing intermolecular interactions taking place in molecular complexes from both structural and energetic points of view. The transition from bi-molecular complex to microsolvation and then to condensed phase is shortly addressed.

中文翻译：

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非共价相互作用的挑战：理论与实验相结合以协调准确性和解释


在过去的十年中，许多气相光谱研究都集中在理解模型系统中弱相互作用的本质。尽管非共价相互作用在一些生物和技术过程中发挥着关键作用，但它们的表征和解释仍然远不能令人满意。在这方面，综合实验和计算研究可以发挥不可估量的作用。事实上，与揭示本体或溶剂化系统的性质相关的许多不同问题可以通过分子复合物的实验研究来解决。重点关注生物模型系统与溶剂分子（例如水）的相互作用，由于生物分子的水合控制其结构和作用机制，因此研究含有有限数量水分子的水合系统的分子性质（微溶剂化）是理解溶剂化过程以及结构和反应性如何从气相到溶液变化的基础。尽管氢键可能是自然界中最广泛的相互作用，但其他新兴类别，例如卤素、硫族和磷族相互作用，由于它们在不同领域中发挥的作用而引起了广泛关注。对它们的理解首先需要表征这种相互作用的方向性、强度和性质，并全面分析它们与其他非共价键的竞争。在这篇综述中，展示了最先进的量子化学计算与旋转光谱学相结合如何从结构和能量的角度全面表征分子复合物中发生的分子间相互作用。 很快就解决了从双分子复合物到微溶剂化再到凝聚相的转变。