Synthesis and crystal structure determination of a new 1D polymer adduct of 1,2-di(pyridin-4-yl)ethane, based on B-N dative bonded eight-membered cyclo-1,3,3,5,7,7-hexaphenyl-1,5-dibora-3,7-disiloxane

Abstract

A novel 1D polymer of 1,2-di(pyridin-4-yl)ethane (L₁), connected via B-N dative-bonded adduct with an eight-membered cyclo-1,3,3,5,7,7-hexaphenyl-1,5-dibora-3,7-disiloxane [Ph₆B₂Si₂O₄]·L₁ was synthesized and characterized. The new compound [Ph₆B₂Si₂O₄]·L₁ was prepared by the reaction of cyclo-1,3,3,5,7,7-hexaphenyl-1,5-dibora-3,7-disiloxane and bis(pyridyl)ethane in a mixture of diethyl ether and petroleum ether solvents at reflux. The 1D polymer [Ph₆B₂Si₂O₄]·L₁ was characterized by single-crystal X-ray diffraction, nuclear magnetic resonance, and FT-IR spectroscopy. The single crystal X-ray diffraction studies reveal that the aforementioned compound crystalized in the monoclinic crystal system with a centrosymmetric space group of P2₁/n (no. 14), a = 16.5378(4) Å, b = 12.6201(3) Å, c = 20.4904(5) Å, β = 96.689(2)°, V = 4247.43(18) ų, Z = 4, T = 173.0 K, μ(MoKα) = 0.130 mm^-1, Dcalc = 1.233 g/cm³, 14630 reflections measured (4.96° ≤ 2Θ ≤ 56.424°), 8424 unique (R_int = 0.0235, R_sigma = 0.0460) which were used in all calculations, the final R₁ was 0.0455 (I > 2σ(I)) and wR₂ was 0.1201 (all data). Furthermore, the compound exhibits various noncovalent interactions in the crystal packing, such as intermolecular and intramolecular, as well as hydrogen bonding. This study demonstrates the potential for making novel materials via the combination of cyclodiboradisiloxanes (Lewis acid) and nitrogen-containing ligands (Lewis bases).