Synthesis and Characterization of Novel Macrocycles Based on Cyclobenzoins

Date

2020-05

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Abstract

Cyclic molecules occupied a unique segment of synthetic chemistry in the last few decades. The diversity in their synthetic methodology and functionality supported their significant development to involve organic, inorganic, and supramolecular chemistry. This thesis focuses on the expansion of the research in the recently discovered class of cyclophanes, which was dubbed "cyclobenzoins". In Chapter One, selected research literature is digested to put into perspective the challenges associated with synthetic macrocycles. Some applications of cyclophanes in molecular recognition, organic-inorganic hybrid molecules, polymer science, analytical detection, sensing, and supramolecular assembly, are also discussed. The history of benzoin condensation and the emergence of cyclobenzoin chemistry are summarized as well. In Chapter Two, the reduction of cyclotribenzoin and the oxidation of cyclotetrabenzoin are applied to produce hexaol and octaketone macrocycles, respectively. The exceptional affinity of the crystal structures of the resultant macrocycles to host tetrahedral hydrogen‐bonded water clusters or chlorinated solvent molecules within their extrinsic or intrinsic pores are discussed. In Chapter Three, the full or partial fusion of cyclic octaketone with ortho‐diamines to produce π‐conjugated cyclic oligoazaacenes macrocycles is discussed. The diversity in crystal structures due to the incorporation of different motifs into the cyclic backbone is examined, as well as the optical and electronic properties of selected cyclic conjugated systems. In Chapter Four, eight arylhydrazone arms are appended to the bridges between the phenyl rings in the octaketone scaffold. The crystal structures and crystal packing of the resulting molecules are examined and their dynamic 1H NMR analyses are studied. In summary, the chemistry of cyclobenzoins is expanded to include the host-guest chemistry, coordination polymers, and crystalline porous materials, as well as the novel optical and electronic properties resulting from the enlarged cyclic conjugated systems with azaacene subunits.

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Keywords

macrocycles, cyclobenzoins, oligoazaacene, hydrazone

Citation

Portions of this document appear in: Alrayyani, Maymounah, and Ognjen Š. Miljanić. "Benzoins and cyclobenzoins in supramolecular and polymer chemistry." Chemical communications 54, no. 85 (2018): 11989-11997. And in: Alrayyani, Maymounah, Xiqu Wang, and Ognjen Š. Miljanić. "Confinement of Water Pentamers within the Crystals of a Reduced Cyclotribenzoin." Chemistry–A European Journal 23, no. 65 (2017): 16476-16478. And in: Hahn, Sebastian, Maymounah Alrayyani, Anna Sontheim, Xiqu Wang, Frank Rominger, Ognjen Š. Miljanić, and Uwe HF Bunz. "Synthesis and Characterization of Heterobenzenacyclo‐octaphanes Derived from Cyclotetrabenzoin." Chemistry–A European Journal 23, no. 44 (2017): 10543-10550.