The conformational equilibria and IR isomerisation processes of glycolaldehyde (HOCH₂CHO) conformers have been studied at low temperature in nitrogen cryogenic matrix. The effects of selective IR irradiation, in the ν_OH${\nu }_{\mathit{OH}}$ and ν_CH${\nu }_{\mathit{CH}}$ domains, have been followed by FTIR spectroscopy. After deposition the main form is the most stable one, CC (Cis-Cis), which features an intramolecular hydrogen bond. Upon selective IR irradiation, this latter form is able to interconvert into two open forms, those called TT (Trans–Trans), and TG (Trans-Gauche). From TT and TG forms, no recovering (by tunneling, dark process, irradiation, annealing, etc.) of the initial state (i.e. CC regeneration) has been observed. However, a TT ⇌ TG thermal equilibrium is observed with a standard reaction enthalpy about 0.37 kJ mol⁻¹.

中文翻译：

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氮基质中红外诱导的乙醇醛光化学

已经在低温下在氮气低温基质中研究了乙醇醛（HOCH ₂ CHO）构象异构体的构象平衡和IR异构化过程。选择IR照射的影响，在ν _OH${\nu }_{\mathit{哦}}$和ν _CH${\nu }_{\mathit{CH}}$领域，之后是FTIR光谱学。沉积后，主要形式是最稳定的形式，CC （Cis-Cis），具有分子内氢键。在选择性的IR照射下，后一种形式可以相互转换为两种开放形式，即TT （反式－反式）和TG （反式－高雪氏）。从TT和TG形式，未观察到初始状态（即CC再生）的恢复（通过隧穿，暗处理，辐照，退火等）。然而，在约0.37kJ mol ^-1的标准反应焓下观察到TT TG热平衡。