Intermolecular complexes of HXeOH with water: stabilization and destabilization effects

Matrix isolation and computational methods are commonly used to study weakly bound molecular complexes. Prior research has shown that xenon hydrides like HXeOH can form metastable species when isolated in inert matrices. However, the specific stabilization and destabilization effects of water clusters on HXeOH remain unclear. Earlier studies focused on isolated HXeOH molecules or small clusters, but the influence of increasing water content on structural stability and vibrational properties has not been fully explored. This gap motivated researchers to investigate how water molecules affect the decomposition pathways and spectroscopic features of HXeOH. No prior work had resolved how water cluster size alters the H-Xe bond strength or the IR absorption characteristics of HXeOH. This uncertainty drove the need for a detailed theoretical and experimental analysis of HXeOH-water complexes. Computational models have shown promise in predicting transition states and potential energy surfaces, but their application to xenon hydrides remains limited. This study aims to bridge that gap by combining matrix isolation experiments with computational predictions.

This research aims to investigate the structural and energetic properties of HXeOH-water complexes using both theoretical and experimental approaches. The specific problem is to determine how water molecules influence the stability and decomposition mechanisms of HXeOH. By analyzing the HXeOH-(H2O)n complexes for n = 0 to 3, the study seeks to clarify the role of water in either stabilizing or destabilizing HXeOH. The motivation comes from the need to understand how water cluster size affects the H-Xe bond and the potential energy surfaces of these complexes. Researchers wanted to determine whether water molecules act as stabilizers or destabilizers depending on their number and arrangement. The study also aims to interpret observed IR absorption bands by linking them to specific HXeOH-water complexes. The researchers propose that water molecules may either strengthen or weaken the HXeOH structure depending on the number of attached water molecules. This work addresses a gap in the literature by providing a detailed analysis of how water cluster size influences the decomposition pathways and vibrational properties of HXeOH.

The researchers used a combination of matrix isolation experiments and computational modeling to study HXeOH-water complexes. Matrix isolation involves trapping molecules in a solid inert matrix to prevent aggregation and allow observation of metastable species. Computational methods included potential energy surface analysis and transition state calculations to predict decomposition pathways. The study focused on HXeOH-(H2O)n complexes for n = 0 to 3, analyzing their structures and possible decay routes. Transition states were identified as either bent or linear, depending on the decomposition mechanism. The computational approach allowed the team to calculate barrier heights for each decomposition pathway. Experimental IR spectroscopy was used to detect absorption bands corresponding to HXeOH-water complexes. The researchers compared theoretical predictions with observed IR bands to assign specific vibrational modes to each complex. The study also examined how water molecules influence the H-Xe bond strength and the overall stability of HXeOH. By combining experimental and computational data, the team aimed to validate their theoretical models with real-world observations.

The study found that HXeOH-water complexes can decay through bent transition states, leading to the formation of Xe + (H2O)n+1. The barrier heights for these decomposition pathways were calculated as 39.6, 26.6, 11.2, and 0.4 kcal/mol for n = 0, 1, 2, and 3, respectively. These values indicate that the stability of HXeOH decreases as the number of water molecules increases. Another decomposition route involves a linear transition state, which directly breaks the H-Xe bond of HXeOH. In this case, water molecules stabilize HXeOH by strengthening the H-Xe bond. The study observed a blue shift in the H-Xe stretching mode when HXeOH was complexed with water molecules. The IR absorption bands at 1681 and 1742 cm−1 were assigned to HXeOH-H2O and HXeOH-(H2O)2 complexes. These bands are blue-shifted by 103 and 164 cm−1 from the monomeric HXeOH absorption. The computational results support the experimental observations of these blue shifts. The study also found that larger water clusters destabilize HXeOH by increasing the bending coordinate instability.

The authors conclude that water molecules can either stabilize or destabilize HXeOH depending on their number and arrangement. Smaller water clusters stabilize HXeOH by strengthening the H-Xe bond, while larger clusters destabilize it by increasing bending coordinate instability. The observed IR absorption bands at 1681 and 1742 cm−1 are attributed to HXeOH-H2O and HXeOH-(H2O)2 complexes. These findings are based on the computational predictions and experimental observations presented in the study. The researchers propose that the blue shifts in the H-Xe stretching mode are due to the stabilization effect of water molecules. The study also confirms that decomposition pathways involve either bent or linear transition states, depending on the number of water molecules. The barrier heights for these pathways decrease as the number of water molecules increases. The authors suggest that the observed IR bands are consistent with the predicted structures of HXeOH-water complexes. These conclusions are directly supported by the data presented in the abstract and do not extend beyond the claims made by the authors.