Supplementary material for the article: Stojanović, M.; Baranac-Stojanović, M. Aromaticity of Diazaborines and Their Protonated Forms. J. Org. Chem. 2016, 81 (1), 197–205. https://doi.org/10.1021/acs.joc.5b02499

Supplementary material for: [https://doi.org/10.1021/acs.joc.5b02499]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2022

The effect of two types of dibenzoannulation of pentalene on molecular energies and magnetically induced currents

The effect of two types of dibenzo-fusion of pentalene in the singlet and triplet states on its molecular energies and magnetically induced ring currents was examined via density functional calculations. The isomerization energy decomposition analysis (IEDA) together with the calculated aromaticity indices (NICS(1) zz , HOMA and FLU π ), estimation of resonance energies (RE) and extra cyclic resonance energies (ECRE) via the NBO method, and the NICS-XY-scans revealed that the π-electronic system is the most important factor controlling the molecular energies. The [a,f] topology features greater delocalization, which results in two opposing effects: larger ECRE, but weaker π-bonding. The latter is mainly responsible for the higher energy of [a,f]-dibenzopentalene (DBP) (ΔE iso = 21.7 kcal mol -1 ), with the other effects being σ-orbital and electrostatic interactions. The reversal of energetic stability in the triplet states (ΔE iso = -10.8 kcal mol -1 ) mainly comes from the reduced Pauli repulsion in [a,f]-DBP, which stabilizes the unpaired spin density over the central trimethylenemethane subunit vs. the central pentalene subunit in [a,e]-DBP. Although the [a,e] topology only reduces the diatropic and paratropic currents of the elementary subunits, benzene and pentalene, the [a,f] topology also creates strong global paratropicity involving the benzene rings. Both DBP isomers are characterized by global and smaller semi-global and local diatropic currents in the triplet state.This is the peer-reviewed version of the following article: Baranac-Stojanović, M.; Stojanović, M. The Effect of Two Types of Dibenzoannulation of Pentalene on Molecular Energies and Magnetically Induced Currents. Physical Chemistry Chemical Physics 2019, 21 (6), 3250–3263. [https://doi.org/10.1039/c8cp07875k

Supplementary data for article: Baranac-Stojanović, M.; Stojanović, M. Does Aromaticity Account for an Enhanced Thermodynamic Stability? The Case of Monosubstituted Azaborines and the Stereoelectronic Chameleonism of the NH2 Group. Physical Chemistry Chemical Physics 2019, 21 (18), 9465–9476. https://doi.org/10.1039/c9cp01011d

Supplementary material for: [https://pubs.rsc.org/en/content/articlelanding/2019/CP/C9CP01011D#!divAbstract]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3128]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3130

Supplementary data for article: Baranac-Stojanović, M.; Stojanović, M. H-1 NMR Chemical Shifts of Cyclopropane and Cyclobutane: A Theoretical Study. Journal of Organic Chemistry 2013, 78 (4), 1504–1507. https://doi.org/10.1021/jo3025863

Supporting information for: [https://doi.org/10.1021/jo3025863]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1604

Supplementary material for the article: Stojanović, M.; Baranac-Stojanović, M. Mono BN-Substituted Analogues of Naphthalene: A Theoretical Analysis of the Effect of BN Position on Stability, Aromaticity and Frontier Orbital Energies. New Journal of Chemistry 2018, 42 (15), 12968–12976. https://doi.org/10.1039/c8nj01529e

Supplementary material for: [https://doi.org/10.1039/c8nj01529e]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2227]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3240

Does aromaticity account for an enhanced thermodynamic stability? The case of monosubstituted azaborines and the stereoelectronic chameleonism of the NH2 group

This work was initiated by the increasing interest in BN/CC isosterism and by the long-lasting interest in the concepts of aromaticity and substituent effects. We have theoretically examined the aromaticity and stability of monosubstituted BN isosters of benzene, the three isomeric azaborines. The results provide insight into the effect of substitution on two basic molecular properties, which are influenced, here, by the substituent effects and by the B/N relationship in the ring. The results, along with other examples in the literature, also warn chemists that the general belief that aromaticity accounts for enhanced thermodynamic stability is not always true. The stability of cyclic, conjugated compounds depends on several effects, and only one of them is aromaticity. In addition, our calculations predict a switching of electronic properties of the NH 2 group from the usual p-electron donor to a π-electron acceptor when it is moved from the B/C atoms to the nitrogen atom in all isomers, or C6 in 1,3-azaborine. This is the result of the conformational change that places the N LP in the plane of the ring and the NH bonds in a favourable spatial position to act as acceptors of π-electron density.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3131]This is the peer-reviewed version of the following article: Baranac-Stojanović, M.; Stojanović, M. Does Aromaticity Account for an Enhanced Thermodynamic Stability? The Case of Monosubstituted Azaborines and the Stereoelectronic Chameleonism of the NH2 Group. Physical Chemistry Chemical Physics 2019, 21 (18), 9465–9476. [https://doi.org/10.1039/c9cp01011d

Supplementary material for the article: Stojanović, M.; Baranac-Stojanović, M. Mono BN-Substituted Analogues of Naphthalene: A Theoretical Analysis of the Effect of BN Position on Stability, Aromaticity and Frontier Orbital Energies. New Journal of Chemistry 2018, 42 (15), 12968–12976. https://doi.org/10.1039/c8nj01529e

Supplementary material for: [https://doi.org/10.1039/c8nj01529e]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2227]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3240

Supplementary data for article: Baranac-Stojanović, M.; Stojanović, M. Substituent Effects on Cyclic Electron Delocalization in Symmetric B- and N- Trisubstituted Borazine Derivatives. RSC Advances 2013, 3 (46), 24108–24117. https://doi.org/10.1039/c3ra44189j

Supplementary material for: [https://doi.org/10.1039/c3ra44189j]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1433

A theoretical study on borenium ion affinities toward ammonia, formaldehyde and chloride anions

Various borenium ion affinities toward three ligands (L' = NH3, HCHO and Cl-) have been evaluated by DFT calculations in the gas-phase and in solvent (CH2Cl2). The gas-phase results have been rationalized on the basis of quantitative decomposition of the total binding energy into contributions from electrostatic, orbital, dispersion and Pauli interactions, and energy needed to deform the interacting fragments from their optimal geometry to that they adopt in an adduct. Twenty six borenium cations, differing in the type of the two R/R' substituents covalently bound to the boron atom and the neutral stabilizing ligand L, have been examined. With a few exceptions, the most important stabilizing interaction is electrostatic, more pronounced in the case of the charged ligand Cl-. Next come orbital interactions, involving the coordinate covalent bond formation, other charge transfer interactions between the cation and ligand, and polarization. Dispersion forces provide the smallest attraction, except in four complexes with long B-L' distances. We present how substituent (R/R')/ligand (L) variations affect binding enthalpies (Delta H)/energies (Delta E). Our results also show that the observed trend in the magnitudes of Delta Hs/Delta Es represents an interplay of the above mentioned (de) stabilizing energies, and can be explained by consideration of the boron-ligand distance and all charge/orbital interactions, rather than partial ones involving boron and ligand L'. Under solvent conditions, the Cl- affinities are drastically reduced and made very similar to NH3 affinities, but still larger than HCHO affinities.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3330

Supplementary data for article: Baranac-Stojanović, M.; Stojanović, M. Magnetic Anisotropy of the C-C Single Bond. Chemistry. A European Journal 2013, 19 (13), 4249–4254. https://doi.org/10.1002/chem.201204267

Supporting information for: [https://doi.org/10.1002/chem.201204267]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1616