We report for the first time the application of chlorofullerene C₆₀Cl₆ as a substrate for straightforward preparation of highly water-soluble fullerene derivatives, promising compounds for investigation of the biological action of fullerenesin vitro and in vivo. Methyl esters of phenylacetic and benzylmalonic acids were used as reagents in the Friedel–Crafts arylation of C₆₀Cl₆ that resulted in the corresponding C₆₀(Ar)₅Cl compounds with 50–60% yields. The following cleavage of ester groups in phenylacetic and benzylmalonic residues was accomplished almost quantitatively to yield the corresponding fullerene-based acids bearing 5 and 10 carboxylic groups, respectively. The relatively-low solubility of these acids in water can be strongly enhanced (up to 150–200 mg ml^–1) by their conversion to salts with alkali metal cations. These fullerene salt derivatives showed pronounced anti-HIV action and low toxicity; these two findings point to the necessity for further investigation of the biological properties of the here-reported compounds.

Bis(diphenylphosphino)methane copper(I) tetrahydroborate was synthesized by ligands exchange in bis(triphenylphosphine) copper(I) tetrahydroborate, and characterized by XRD, FTIR, NMR spectroscopy. According to XRD the title compound has dimeric structure, [(μ₂-dppm)₂Cu₂(η₂-BH₄)₂], and crystallizes as CH₂Cl₂ solvate in two polymorphic forms (orthorhombic, 1, and monoclinic, 2) The details of molecular geometry and the crystal-packing pattern in polymorphs were studied. The rare Twisted Boat-Boat conformation of the core Cu₂P₄C₂ cycle in 1 is found being more stable than Boat-Boat conformation in 2.