Supplementary data for article: Blagojević, J. P.; Zarić, S. D. Stacking Interactions of Hydrogen-Bridged Rings-Stronger than the Stacking of Benzene Molecules. Chemical Communications 2015, 51 (65), 12989–12991. https://doi.org/10.1039/c5cc04139b

Supplementary material for: [https://doi.org/10.1039/c5cc04139b]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1747]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3424

Стекинг интеракције прстенова формираних водоничним везивањем потпомогнутим резонанцијом

Resonance-assisted hydrogen-bridged rings are often found in crystal structures in parallel alignment; 44% of all crystal structuresfound in Cambridge structural database, that contain this ring type, form parallel contacts. Distances betw een ring planes are typical for stacking (3.0-4.0 Å) and rings are in anti orientation. Quantum chemical calculations of th e stacking interaction energies are performed using different methods that are in good agreement with CCSD(T)/CBS methods, on model systems composed on dimers of molecules whose derivatives are the most common in crystal structures. The stro ngest calculated interactions (up to -5.1 kcal/mol) are comparable with stacking interactions of saturated hydrogen-bridged rings (-4.9 kcal/mol [1]) and stacking interactions between saturated hydrogen-bridged rings and C6-aromatic rings (-4.4 kcal/mol [2]), as well as with hydrogen bonds between water molecules (-4.8 kcal/mol [3]). Results indicate that energies of stack ing interactions of resonance-assisted hydrogen-bridged rings are not substantially different than energies of stacking interactions between saturated hydrogen-bridged rings

Stacking interactions of planar hydrogen-bridged rings

Прстенови формирани водоничним везивањем у свом саставу имају једну унутармолекулску водоничну везу. С обзиром на планарну геометрију ови прстенови потенцијално могу да граде паралелне стекинг интеракције. У овој тези проучаване су паралелне стекинг интеракције неколико типова прстенова формираних водоничним везивањем, како између два оваква прстена, тако и између ових прстенова и С6-ароматичних прстенова. Претрагом Кембричке базе структурних података утврђено је да 27% структура које садрже планарне засићене прстенове формиране водоничним везивањем, у којима су сви атоми унутар прстена делови планарних група, гради стекинг интеракције, при којима су диполни моменти антипаралелни. Истовремено, стекинг интеракције чине и велику већину контаката ових прстенова у кристалним структурама (86%). Врло тачним квантнохемијским методама утврђено је да ове интеракције могу бити релативно јаке-и до - 4,9 kcal/mol, што је значајно јача стекинг интеракција него у димеру бензена (-2,7 kcal/mol). Исти је проценат структура (27%) засићених планарних прстенова формираних водоничним везивањем, у којима се јавља бар један атом који је део непланарног система, које граде стекинг интеракције. Захваљујући присуству непланарних група могуће је грађење додатних међумолекулских интеракција, од којих су најзаступљеније водоничне везе. Интеракције димера ове врсте прстенова, у којима се јавља и међумолекулска водонична веза, су врло јаке-и до -9,7 kcal/mol. Постојање додатних водоничних веза не утиче на паралелну оријентацију и растојање између равни прстенова у кристалним структурама, већ само доприноси јачини интеракција. Стекинг интеракције С6-ароматичних прстенова и засићених планарних прстенова формираних водоничним везивањем су веома заступљене у кристалним структурама у којима постоје ове две врсте прстенова и чине 45% свих контаката ова два типа прстенова у кристалним структурама. Енергија стекинг интеракције бензена и прстенова формираних водоничним везивањем (-4,4 kcal/mol) је упоредива са међусобним стекинг интеракцијама прстенова формираних водоничним везивањем (-4,9 kcal/mol) и значајно јача од стекинг интеракције димера бензена (-2,7 kcal/mol), што није очекивано, с обзиром да молекул бензена не поседује диполни момент. Стекинг интеракције су врло заступљене у кристалним структурама прстенова формираних водоничним везивањем потпомогнутим резонанцијом, с обзиром да се јављају у 40% свих структура у којима постоје ови прстенови и 91% свих контаката ове врсте прстенова. Енергије интеракција су истог реда величине као енергије интеракција засићених планарних прстенова формираних водоничним везивањем (-4,9 kcal/mol), с обзиром да најнижа израчуната енергија интеракције за димер прстенова формираних водоничним везивањем потпомогнутим резонанцијом износи -5,1 kcal/mol, што значи да присуство π-система нема пресудног утицаја на јачине стекинг интеракција прстенова формираних водоничним везивањем.The hydrogen-bridged rings have an intramolecular hydrogen bond in the ring. Given the planar geometry, these rings can potentially form parallel stacking interaction. In this thesis, the parallel stacking interactions of several types of hydrogen-bridged rings, between two such rings, and between these rings and C6-aromatic rings, were studied. A search of Cambridge Structural Database revealed that in 27% of structures containing planar saturated hydrogen-bridged rings, in which all the atoms within the ring are part of a planar group, the rings form stacking interactions, where all the dipole moments are antiparallel. At the same time, parallel stacking interactions make a large majority of these ring contacts in crystal structures (86%). Very accurate quantum chemical methods show that these interactions can be relatively strong-up to -4.9 kcal/mol, which is considerably stronger than the stacking interaction of benzene dimer (-2.7 kcal/mol). In the same percentage of structures (27%) of saturated planar hydrogen-bridged rings, having at least one atom, that is a part of a nonplanar system, the rings form stacking interactions. Nonplanar groups, situated out of the ring plane, can form additional intermolecular interactions, the most common being hydrogen bonds. Interactions of planar saturated hydrogen-bridged ring dimers, that additionally form intermolecular hydrogen bonding, are very strong, up to -9.7 kcal/mol. Hence, intermolecular hydrogen bonds do not affect the parallel alignment or interplanar distance of hydrogen-bridged rings in crystal structures, but only contribute to the interaction strength. Stacking interactions of C6-aromatic rings and saturated planar hydrogen-bridged rings are very frequent in crystal structures that contain both ring types and they make 45% of all contacts of these rings. Interaction energy between benzene and hydrogen-bridged rings (-4.4 kcal/mol) is comparable with mutual stacking interactions of hydrogen-bridged ring dimers (-4.9 kcal/mol) and it is considerably lower than the energy of benzene dimer stacking (-2.7 kcal/mol). That is expected, since benzene molecule does not possess dipole moment. Stacked structures are very common in crystals of resonance-assisted hydrogen-bridged rings, since they form in 40% of structures and from 91% of the mutual contacts of these rings. Interaction energies are of the same order of magnitude as the energies of saturated planar hydrogen-bridged ring dimers (-4.9 kcal/mol), since the lowest calculated interaction energy of a resonance-assisted hydrogen-bridged ring dimer is -5.1 kcal/mol, meaning that the presence of a π-system does not have large influence on stacking interactions of hydrogen-bridged rings

Supplementary data for the article: Blagojević, J. P.; Janjić, G. V.; Zarić, S. D. Very Strong Parallel Interactions between Two Saturated Acyclic Groups Closed with Intramolecular Hydrogen Bonds Forming Hydrogen-Bridged Rings. Crystals 2016, 6 (4). https://doi.org/10.3390/cryst6040034

Supplementary material for: [https://doi.org/10.3390/cryst6040034]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1928

Supplementary material for the article: Blagojević, J. P.; Veljković, D.; Zarić, S. D. Stacking Interactions between Hydrogen-Bridged and Aromatic Rings: Study of Crystal Structures and Quantum Chemical Calculations. CrystEngComm 2017, 19 (1), 40–46. https://doi.org/10.1039/c6ce02045c

Supplementary material for:[https://doi.org/10.1039/c6ce02045c ]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2380]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3246

Supplementary material for the article: Blagojević, J. P.; Veljković, D.; Zarić, S. D. Stacking Interactions between Hydrogen-Bridged and Aromatic Rings: Study of Crystal Structures and Quantum Chemical Calculations. CrystEngComm 2017, 19 (1), 40–46. https://doi.org/10.1039/c6ce02045c

Supplementary material for:[https://doi.org/10.1039/c6ce02045c ]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2380]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3246

Supplementary data for the article: Filipović, J. P. B.; Hall, M. B.; Zarić, S. D. Stacking Interactions of Resonance-Assisted Hydrogen-Bridged Rings and C6-Aromatic Rings. Phys. Chem. Chem. Phys. 2020, 22 (24), 13721–13728. https://doi.org/10.1039/D0CP01624A

Supplementary material for: [https://doi.org/10.1039/d0cp01624a]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4060

Supplementary material for the article: Stanković, I. M.; Blagojević Filipović, J. P.; Zarić, S. D. Carbohydrate – Protein Aromatic Ring Interactions beyond CH/π Interactions: A Protein Data Bank Survey and Quantum Chemical Calculations. Int. J. Biol. Macromol. 2020, 157, 1–9. https://doi.org/10.1016/j.ijbiomac.2020.03.251

Supplementary material for: [https://doi.org/10.1016/j.ijbiomac.2020.03.251]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3983]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3984

Supplementary data for article: Blagojević, J. P.; Zarić, S. D. Stacking Interactions of Hydrogen-Bridged Rings-Stronger than the Stacking of Benzene Molecules. Chemical Communications 2015, 51 (65), 12989–12991. https://doi.org/10.1039/c5cc04139b

Supplementary material for: [https://doi.org/10.1039/c5cc04139b]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1747]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3424

Stacking Interactions of Resonance-Assisted Hydrogen-Bridged (RAHB) Rings; Significant Attraction at Large Displacements

Some systems that form stacking interactions conserve large portion of their strength upon shifting to large horizontal displacements, which might have implications on molecular recognition.[1] The possibility of RAHB/RAHB and RAHB/C6-aromatic systems to form stacking at large horizontal displacements is studied in this work. Large part of parallel RAHB/RAHB and RAHB/C6-aromatic contacts found in the Cambridge Structural Database (CSD) are classified as large offset stacking (44% and 47%, respectively).[2] Crystal structures of both RAHB/RAHB and RAHB/C6-aromatic systems are organized into parallel layers, unlike benzene crystal structures. Quantum chemical calculations show that the contacts at large offsets found in the CSD are not just the consequence of crystal packing. The calculated potential energy curves reveal the existence of certain stabilizations at large offsets (plateaus and even shallow minima). The large offset stacking interaction energies can be significant even at interplane separations typical for stacking (3.0-4.0 Å), or slightly smaller (Figure 1). In some systems, up to 66% of the strongest calculated interaction energy can be preserved upon shifting to large offsets.[2