Abstract

Herein, we report on the role of H-bonding in the growth of ammonium dihydrogen phosphate (ADP) crystals with additives like malic acid (MA), succinic acid (SA) and ascorbic acid (ASA). Pure and the additives doped ADP single crystals grown by natural evaporation method at room temperature are analysed for the intermolecular interactions and are examined by powder X-ray diffraction. The results confirm that the samples are single crystalline with additional planes due to additives in the solution. DSC thermograms for ADP and doped ADP crystals show that the additives increase the stability of the crystal and the latent heat of fusion (ΔH_f) of the samples depend inversely on the H-bond distances. Results from the FT-IR spectra indicate minimal influence of additives on the grown ADP crystal. Changes in the O–H–O hydrogen bond reflect the local environment. The additives show a marginal influence on the dipole moment values, with the doped ADP showing higher values than pure ADP. The NLO properties exhibit a reverse trend, with ADP + MA showing nearly seven times the value of pure ADP crystal. The enhanced stability and NLO property of the doped ADP compared with pure ADP demonstrate that the presence and strength of H-bonds play a key role in the overall structure of ADP.

Graphical Abstract

中文翻译：

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通过氢键添加剂调节磷酸二氢铵的晶体生长

摘要

在此，我们报告了氢键在含有苹果酸（MA）、琥珀酸（SA）和抗坏血酸（ASA）等添加剂的磷酸二氢铵（ADP）晶体生长中的作用。分析了室温下自然蒸发法生长的纯ADP单晶和添加添加剂的ADP单晶的分子间相互作用，并通过粉末X射线衍射进行了检查。结果证实，由于溶液中的添加剂，样品是具有额外平面的单晶。ADP 和掺杂 ADP 晶体的 DSC 热分析图表明，添加剂提高了晶体的稳定性，并且样品的熔化潜热 (Δ H _f ) 与氢键距离成反比。FT-IR 光谱结果表明添加剂对生长的 ADP 晶体的影响极小。O-H-O氢键的变化反映了当地的环境。添加剂对偶极矩值显示出边际影响，掺杂的 ADP 显示出比纯 ADP 更高的值。NLO 特性呈现出相反的趋势，ADP + MA 显示出纯 ADP 晶体值的近七倍。与纯ADP相比，掺杂ADP增强的稳定性和非线性光学性质表明氢键的存在和强度在ADP的整体结构中起着关键作用。

图形概要