TY - JOUR

T1 - Structure and bonding in molecular and ionic complexes of iodine Monochloride with pyrazine

AU - Давыдова, Елена Иоановна

AU - Помогаева, Анна Владимировна

AU - Спиридонова, Дарья Валерьевна

AU - Лисовенко, Анна Сергеевна

AU - Тимошкин, Алексей Юрьевич

PY - 2026/1/1

Y1 - 2026/1/1

N2 - Structures of molecular and ionic compounds of ICl with pyrazine (pyz) have been established for the first time by X-ray diffraction structural analysis. In the molecular complex ICl∙pyz∙ICl (1) pyrazine serves as bidentate nonchelating ligand. The ionic complexes [Hpyz]+[ICl2]− (2) and [I2∙pyz…Hpyz∙I2]Cl (3) exhibit distinct coordination bonding patterns. The structural motif of 2 features infinite […pyz…H-pyz…]+ hydrogen bonded cationic chains and distinct [ICl2]− counterions, which interact with cationic chain not only through electrostatic anion–cation attraction but also via weak Csingle bondH⋯Cl hydrogen bonds.In very peculiar structure of 3, the iodine molecules act as bidentate Lewis acid, bridging the hydrogen-bonded cations [pyz…Hpyz]+ and the chloride anions in the infinite, almost linear chains (…I2…pyz…Hpyz+…I2…Cl−…I2∙pyz…Hpyz+…I2…Cl−…)∞. Quantum chemical computations allowed to rationalize reactivity and establish a chemical bonding in the compounds. The dominant binding motif is governed by hydrogen bonds in [pyz…Hpyz]+ fragments and donor-acceptor halogen bonds Cl− → I–I ← N, where iodine molecules serve as bidentate Lewis acids. Unusual linear arrangement of two Lewis acids I2∙pyz and I2∙Hpyz+ around Cl− anion in 3 is facilitated due to packing effects forced by π-π staking between peripheral pyrazine rings.

AB - Structures of molecular and ionic compounds of ICl with pyrazine (pyz) have been established for the first time by X-ray diffraction structural analysis. In the molecular complex ICl∙pyz∙ICl (1) pyrazine serves as bidentate nonchelating ligand. The ionic complexes [Hpyz]+[ICl2]− (2) and [I2∙pyz…Hpyz∙I2]Cl (3) exhibit distinct coordination bonding patterns. The structural motif of 2 features infinite […pyz…H-pyz…]+ hydrogen bonded cationic chains and distinct [ICl2]− counterions, which interact with cationic chain not only through electrostatic anion–cation attraction but also via weak Csingle bondH⋯Cl hydrogen bonds.In very peculiar structure of 3, the iodine molecules act as bidentate Lewis acid, bridging the hydrogen-bonded cations [pyz…Hpyz]+ and the chloride anions in the infinite, almost linear chains (…I2…pyz…Hpyz+…I2…Cl−…I2∙pyz…Hpyz+…I2…Cl−…)∞. Quantum chemical computations allowed to rationalize reactivity and establish a chemical bonding in the compounds. The dominant binding motif is governed by hydrogen bonds in [pyz…Hpyz]+ fragments and donor-acceptor halogen bonds Cl− → I–I ← N, where iodine molecules serve as bidentate Lewis acids. Unusual linear arrangement of two Lewis acids I2∙pyz and I2∙Hpyz+ around Cl− anion in 3 is facilitated due to packing effects forced by π-π staking between peripheral pyrazine rings.

KW - Iodine monochloride

KW - Pyrazine

KW - Complexes

KW - Structures

KW - Bonding

KW - Bonding

KW - Complexes

KW - Iodine monochloride

KW - Pyrazine

KW - Structures

UR - https://www.sciencedirect.com/science/article/pii/S0020169325003937

UR - https://www.mendeley.com/catalogue/b27708d4-3d44-3db9-aff4-a83e2365884d/

U2 - 10.1016/j.ica.2025.122927

DO - 10.1016/j.ica.2025.122927

M3 - Article

VL - 589

JO - Inorganica Chimica Acta

JF - Inorganica Chimica Acta

SN - 0020-1693

IS - 1

M1 - 122927

ER -