The properties of single site-controlled InGaAsN quantum wires (QWRs)-both untreated and irradiated with atomic hydrogen-are probed by micro-magnetophotoluminescence spectroscopy. The strong anisotropy of the diamagnetic shift measured for different orientations of the applied magnetic field confirms the one-dimensional nature of the QWR carrier wave function. In addition, the strain reduction associated with N incorporation is found to promote a larger indium intake in the QWR, enabling the realization of site-controlled QWRs emitting at long (>= 1.3 mu m), technologically relevant wavelengths.