Supplementary material for the article: Milovanović, M. M.; Andrić, J. M.; Medaković, V. B.; Djukic, J.-P.; Zarić, S. D. Investigation of Interactions in Lewis Pairs between Phosphines and Boranes by Analyzing Crystal Structures from the Cambridge Structural Database. Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials 2018, 74 (3), 255–263. https://doi.org/10.1107/S2052520618003736

Supplementary material for: [https://doi.org/10.1107/S2052520618003736]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2157

The NH···O Interaction of Coordinated Ammonia and Ethylenediamine

The Cambridge Structural Database (CSD) search was used to find contacts of coordinated ammonia and coordinated ethylenediamine with water molecule.[1,2] The criteria for contacts were the dHO distance less than 4.0 Å and the angle α (N-H∙∙∙O) larger than 110°. The results from CSD search have shown that the peak of dHO distance for coordinated ammonia is in the 2.0 Å to 2.2 Å range, while the most abundant dHO distance for ethylenediamine is shorter, lying within the 1.8 Å to 2.0 Å range. The distribution of α angle for coordinated ammonia is without clear preference while for ethylenediamine tendency for more linear angle is pronounced. The interaction energy of free ammonia and of free ethylenediamine with water molecule are the same, -2.3 kcal/mol. The interaction energies for coordinated ammonia and coordinated ethylenediamine are significantly stronger. The interaction energies for singly and doubly charged ammonia complexes are -5.0 kcal/mol and -10.7 kcal/mol, respectively. The interaction energies for neutral, singly and doubly charged ethylenediamine are -6.7 kcal/mol, -11.8 kcal/mol and -19.9 kcal/mol, respectively. The interaction for ethylenediamine is stronger than for ammonia molecule due to somewhat stronger electrostatic interactions

Structure of water molecule and water hydrogen bonding: joint Cambridge Structural Database and ab-initio calculations study

In this study we performed analysis of non-coordinated water containing structures archived in Cambridge Structural Database (CSD), as well as ab-initio calculations on a range of bond lengths and bond angles of water molecule and water dimers

New aspects of Hydrogen Bonding: Antiparallel OH/OH Interactions. Cases of Water/Water, Water/Alcohol and Alcohol/Alcohol Dimers.

According to IUPAC definition, the hydrogen bond ‘is an attractive interaction usually presented as X—H Y—Z, where the electropositive hydrogen atom is located between two electronegative species X and Y.[1] The stability of hydrogen bonds varies in the range from -0.2 to -40 kcal/mol depending on the nature of the X and Y species and the geometry of the hydrogen bond. In this presentation, new modes of hydrogen bonding will be discussed. Namely, it was found that nearly 20% of all crystal structures, from Cambridge Structural Database, containing water-water or alcohol dimers, possess, so far, unusual antiparallel OH/OH interactions. The interaction energies of this type of hydrogen bonding (Figure 1.) are systematically calculated at CCSD(T)/CBS level of theory.[2] It was shown that the strength of the antiparallel interactions can be similar as the strength of classical hydrogen bonds, i.e. up to – 4.7 kcal/mol. The geometric parameters describing the antiparallel interactions were suggested, as well

Repulsive water-water contacts from Cambridge Structural Database

Water is one of the most important molecules on the Earth. Since water plays a crucial role in many life processes, it is of great importance to understand every aspect of its behavior and interactions with itself and its surroundings. It is known that water molecules can interact via classical hydrogen bonds and antiparallel interactions, with interaction energies of - 5.02 kcal/mol and -4.22 kcal/mol, respectively. Besides these attractive interactions, repulsive interactions were also noticed. In this work, we analyzed repulsive water-water contacts from the Cambridge Structural Database. All interaction energies were calculated at the so- called gold standard, i.e., CCSD(T)/CBS level of theory. It was found that among all water-water contacts, ca. 20% (2035 contacts) are repulsive with interaction energies mainly up to 2 kcal/mol. Most of these repulsive contacts do not belong to two main groups of water-water contacts. Namely, 12.8% of all repulsive contacts can be classified as classical hydrogen bonds, 2.1% to the antiparallel interactions, and the rest (85.3%) as remaining contacts. This study points out that additional attention should be paid when one deals with contacts including water or, eventually, hydrogen atoms in general

Benzene and water – different or similar?

Considering the properties of water and benzene molecules, one can expect very different benzene/benzene and water/water interactions. Benzene does not have a dipole moment, while water does. Analysis of the data in the crystal structures in the Cambridge Structural Database (CSD) revealed the most frequent benzene/benzene and water/water geometries. The majority of the benzene/benzene interactions in the crystal structures in the CSD are stacking interactions with large horizontal displacements, and not geometries that are minima on benzene/benzene potential surface. A large number of the water/water contacts in the CSD are hydrogen bonds, 70% of all attractive water/water interactions. In addition, water/water contacts with two water forming antiparallel interactions are 20% of all attractive water/water contacts. In these contacts, the O-H bonds of water molecules are in antiparallel orientation. In benzene/benzene interactions at large horizontal displacements, two C-H bonds also are in the antiparallel orientation. This shows that although the two molecules are different, both of them form antiparallel interactions with a local O-H and C-H dipole moments

Antiparallel Noncovalent Interactions

In spite of being quite different substances, benzene and water can form similar noncovalent interactions. Analysis of the data in the crystal structures in the Cambridge Structural Database (CSD) revealed similarities in benzene/benzene and water/water interactions, since both benzene/benzene and water/water can form antiparallel interactions. The quantum chemical calculations of potential surface of water/water interactions showed that the minimum is hydrogen bond. Analysis of the data in the crystal structures in the Cambridge Structural Database (CSD) revealed antiparallel water/water interactions, in addition to classical hydrogen bonds (1). The geometries of all water/water contacts in the CSD were analyzed and for all contacts interaction energies were calculated at accurate CCSD(T)/CBS level. The results showed that the most frequent water/water contacts are hydrogen bonds; hydrogen bonds are 70% of all attractive water/water interactions. In addition, water/water contacts with antiparallel interactions are 20% of all attractive water/water contacts. In these contacts O-H bonds of water molecules are in antiparallel orientation (Figure). The quantum chemical calculations of potential surface of benzene/benzene interactions showed two minima stacking (parallel displaced) geometry and T-shaped geometry. Analysis of all benzene/benzene contacts in the crystal structures in the CSD revealed the most frequent benzene/benzene geometries (2). Majority of the benzene/benzene interactions in the CSD are stacking interactions with large horizontal displacements, and not geometries that are minima on benzene/benzene potential surface. In benzene/benzene interactions at large horizontal displacements two C-H bonds are in the antiparallel orientation (Figure). In these O-H and C-H antiparallel interactions two dipoles are in antiparallel orientation enabling close contact of positive and negative regions of the dipoles. Symmetry Adapted Perturbation Theory (SAPT) analysis showed that electrostatic is the largest attractive force in the antiparallel interactions. Antiparallel interactions are also possible between O-H and C-H bonds; in the crystal structures from the CSD these interactions are observed as one of the types of water benzene interactions (3)

Genetic Markers for Coronary Artery Disease

Coronary artery disease (CAD) and myocardial infarction (MI) are recognized as leading causes of mortality in developed countries. Although typically associated with behavioral risk factors, such as smoking, sedentary lifestyle, and poor dietary habits, such vascular phenotypes have also long been recognized as being related to genetic background. We review the currently available data concerning genetic markers for CAD in English and non-English articles with English abstracts published between 2003 and 2018. As genetic testing is increasingly available, it may be possible to identify adequate genetic markers representing the risk profile and to use them in a clinical setting. © 2018 by the authors. Licensee MDPI, Basel, Switzerland

High pressure densities of ethylene glycol and caffeine mixtures

Ethylene glycol is a well-known fluid that is recognized for its application in heat transfer processes [1]. In order to improve its characteristics and performances, adding other particles in the mixture of ethylene glycol and water, such as nanoparticles has been investigated [2]. A substance widespread available, easily distributed and cost effective is caffeine. Caffeine can be recycled from coffee or tea waste, which makes it profitable and sustainable. Literature data state that caffeine addition to ethylene glycol improves its properties as a heat transfer fluid, primarily due to higher heat capacities, higher system fluidity and lower viscosity [3]. This work investigates different thermodynamic properties of caffeine + ethylene glycol mixtures. Densities have been measured at high pressures from (0,1 – 60) MP and at the temperature range (20 - 140) ºC. All measurements were performed using an Anton Paar DMA 5000 HP density meter with a vibrating tube [4]. The obtained results were fitted by the modified Tammann-Tait equation and parameters were used to determine the isothermal compressibility coefficient, the coefficient of isobaric expansion, the internal pressure and the difference of specific heat capacity at constant pressure and constant volume. Experimental values and calculated thermodynamic parameters reported in this work will help in concluding whether the caffeine + ethylene glycol mixtures are good candidates as heat transfer fluids

Water: new aspect of hydrogen bonding in the solid state

All water–water contacts in the crystal structures from the Cambridge Structural Database with dOO 4.0 A˚ have been found. These contacts were analysed on the basis of their geometries and interaction energies from CCSD(T)/CBS calculations. The results show 6729 attractive water–water contacts, of which 4717 are classical hydrogen bonds (dOH 3.0 A˚ and 120 ) with most being stronger than 3.3 kcal mol 1 . Beyond the region of these hydrogen bonds, there is a large number of attractive interactions (2062). The majority are antiparallel dipolar interactions, where the O—H bonds of two water molecules lying in parallel planes are oriented antiparallel to each other. Developing geometric criteria for these antiparallel dipoles ( 1, 2 160 , 80 140 and THOHO > 40 ) yielded 1282 attractive contacts. The interaction energies of these antiparallel oriented water molecules are up to 4.7 kcal mol 1 , while most of the contacts have interaction energies in the range 0.9 to 2.1 kcal mol 1 . This study suggests that the geometric criteria for defining attractive water–water interactions should be broader than the classical hydrogen-bonding criteria, a change that may reveal undiscovered and unappreciated interactions controlling molecular structure and chemistr