1',1''-Dimethyl-4'-(4-methyl-phen-yl)di-spiro-[11H-indeno-[1,2-b]quinoxaline-11,2'-pyrrolidine-3',3''-piperidin]-4''-...

Area of Science:

• Crystallography
• Organic Chemistry
• Supramolecular Chemistry

Background:

• Understanding the three-dimensional structure of organic compounds is crucial for predicting their properties and reactivity.
• Crystal engineering relies on characterizing intermolecular forces to design materials with desired characteristics.

Purpose of the Study:

• To elucidate the detailed molecular and crystal structure of the compound C31H30N4O.
• To investigate the conformational preferences of the pyrrolidine ring and its relationship with the planar quinoxaline and indane moieties.
• To identify and analyze intra-molecular and inter-molecular interactions, including hydrogen bonding and C-H⋯π interactions.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the atomic arrangement of C31H30N4O.
• Analysis of bond lengths, bond angles, and conformational parameters was performed.
• Identification and analysis of non-covalent interactions, such as C-H⋯O, C-H⋯N, and C-H⋯π interactions, were conducted.

Main Results:

• The central pyrrolidine ring exhibits an envelope conformation, with the methylene carbon atom as the flap.
• The quinoxaline and indane rings are planar, with root-mean-square deviations of 0.030 Å and 0.050 Å, respectively.
• Dihedral angles between the pyrrolidine ring mean plane and the quinoxaline/indane rings are 88.25(1)° and 83.76(1)°, respectively.
• Intra-molecular C-H⋯O and C-H⋯N interactions were observed.
• Crystal packing analysis revealed the formation of helical supramolecular chains along the b-axis, driven by C-H⋯π interactions.

Conclusions:

• The study provides a comprehensive structural characterization of C31H30N4O.
• The observed intra-molecular interactions influence the overall molecular conformation.
• Inter-molecular C-H⋯π interactions play a significant role in directing the self-assembly of molecules into helical supramolecular structures in the solid state.