Palladium(II) and platinum(II) complexes of ((2-pyridyl)pyrazol-1-ylmethyl)benzoic acids: Synthesis, Solid state characterisation and biological cytotoxicity

Stacking interactions of resonance-assisted hydrogen-bridged rings and C6-aromatic rings

“…The stacking interactions are mainly connected with aromatic molecules, [1][2][3][4][5][6][7][8][9][10] however it was shown that various rings can form stacking interactions; aliphatic saturated [11][12][13][14][15][16] and unsaturated molecules, 17,18 metal-chelate rings, [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] and hydrogen-bridged rings. [39][40][41][42] 2D materials can also form stacking interactions.…”

“…12 Square-planar metal-chelate rings in crystal structures can form stacking interactions mutually 19,[23][24][25][26][27][32][33][34][35] and with aromatic rings. 19,21,28,32,33 Quantum chemical calculations of interaction energies show that the chelate/chelate stacking interactions (up to -10.34 kcal/mol) 19,33 , are stronger than chelate/benzene interactions (up to -7.52 kcal/mol), 19,32,33 while both of them are stronger than benzene/benzene stacking (-2.73 kcal/mol).…”

Stacking Interactions of Resonance-Assisted Hydrogen-Bridged Rings. A Systematic Study of Crystal Structures and Quantum-Chemical Calculations

“…These facts contribute to widening the concept of stacking interactions, since it was shown , that aromaticity is not essential for stacking. It has been also shown that chelates − or nonaromatic hydrocarbons ,, form strong stacking interactions.…”