Three stable phosphonium salts of 1,4-butanediylebis(triphenylphosphonium) dibromide I, butane-4- bromo-1-(triphenylphosphonium) bromide II and 1,3-propanediylbis(triphenylphosphonium) tetrahydroborate III were synthesized and structurally characterized. Single crystal X-ray diffraction analysis, spectroscopic methods and thermal analysis methods were used for the characterization of titled compounds. Crystallographic data showed that compound I crystallized in the triclinic crystal system Pi with space group and compound II crystallized in the monoclinic crystal system with P21 space c group. The crystal packing structures of I and II were stabilized by various intermolecular interactions, ·p especially of C-H·· contacts. The molecular Hirshfeld surface analysis and 2D fingerprint revealed that the C···H contacts have 24.3 % and 18.4 % contributions in the crystal packings of compounds I and II, respectively. In addition, the H···Br (28.5%) contact has a considerable contribution to the crystal architecture of compound II. Theoretical studies were performed by DFT methods to investigate the structural properties of the titled compounds. The isotopic ratio of boron in tetrahydroborate anion of 1 10 /1 compound III calculated by 1H NMR spectroscopy. The isotopic ratio for B 1B was 19.099 / 80.900 %. Reduction of some carbonyl compounds to corresponding alcohols was performed by compound III and the optimum conditions were determined

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