AROMATIC TETRAHEDRAL BORATE COMPOUNDS FOR LUBRICATING COMPOSITIONS

A lubricating composition includes an oil of lubricating viscosity and an ionic tetrahedral borate compound which includes a cation and a tetrahedral borate anion which includes a boron atom, the boron atom having at least one aromatic bidentate di-oxo ligand. The compound may be represented by formula (I), where R1 and R2 are selected from C1-48 hydrocarbyl groups or together form a substituted or unsubstituted 5- or 6-membered ring; R3 and R4 together represent a substituted or unsubstituted aromatic ring; m is 0 or 1; X is hydrogen, a C1-24 hydrocarbyl group, -OR5, -NHR5, or =O, R5 is a C1-24 hydrocarbyl group; M represents the cation; and n is at least 1. The cation may be selected to provide detergent and/or dispersant properties to the lubricating composition. In the case of ammonium cations, the molecular weight may be 260 g/mol or higher for providing a highly soluble compound, particularly when X is =O.