A 1D helical-chain material Cu6(H2O)7(m-PO3C6H4CO2)41, characterized by a non-centrosymmetric crystal structure, and a 2D lamellar hybrid material Cu(H2O)(m-PO3C6H4CO2H) 2have been synthesised starting from m-phosphonobenzoic acid and copper(II). The pH of the reaction media regulates...