Study the cooperative noncovalent interactions in Lithium-1, 10-Phenanthroline complex, its DFT calculations and Hirschfield surface analysis

ABSTRACT

The new compound [Li(NO₃)(phen)]_n (phen: 1,10-phenanthroline) has been synthesized and characterized by elemental analysis, and single crystal X-ray diffraction. The Li⁺ ion is five coordinated occupied distorted TBP (trigonal bipyramidal) geometry. The Li⁺ ions are bridged by nitrate anions into 1D polymeric chain. The nitrate anions are coordinated to Li⁺ ions through chelating and bridging bidentate mode of binding. There are cooperative noncovalent interactions like strong or weak H-bonding, weak π···π and C‒H···π interactions are involved to form 2D network. Thermal properties of this complex have been completely described by thermo gravimetric analysis (TGA). Both molecular and crystal structures of this compound were compared and discussed the intermolecular interactions by using Hirshfeld surface analysis and 2D-fingerprint plots. The optimized molecular geometry by DFT calculations agrees closely with obtained from the crystallographic study. Hirshfeld surface analysis of compound (I) indicates that H···H, π···π and C‒H···π contacts can account for 30.9, 15.0 and 7.4% respectively of the total Hirshfeld surface area.

KEYWORDS:

• Bridging bidentate
• chelating
• hirshfeld surface
• trigonal bipyramidal
• 2D-fingerprint

Acknowledgements

Rahul Kumar Mudsainiyan is highly thankful to Hindu College, Amritsar Authority specially, Principal (Dr. P. K. Sharma) for financial assistance and providing infrastructure. AKJ is thankful to DST (SERB) for National Post-doctoral fellowship and Indian Institute of Technology, Delhi for providing infrastructure and research facilities.

Supporting information

ORTEP of asymmetric unit of compound (I); packing diagram within the unit cell; 2-D fingerprinting plots showing intermolecular contacts; infrared spectrum of optimized structure using Gaussian 03/ B3LYP/ LanL2DZ basic set; tables of selected bond distances (Å), bond angles (°) and torsion angles (°); tables of d-spacing, intensity and size of important peaks at different 2-theta values; tables of initial and optimized bond distance (Å), bond angle (°) and torsion angles (°) of compound (I). The cif and structure factor data are available from Cambridge structure data base, free of cost, CCDC number = 1400754.