We report new interferometric images of cyclopropenylidene , c–C _ { 3 } H _ { 2 } , towards the young protocluster OMC–2Â FIR 4 . The observations were performed at 82 and 85Â GHz with the NOrthern Extended Millimeter Array ( NOEMA ) as part of the project Seeds Of Life In Space ( SOLIS ) . In addition , IRAM-30m data observations were used to investigate the physical structure of OMC–2Â FIR 4 . We find that the c–C _ { 3 } H _ { 2 } gas emits from the same region where previous SOLIS observations showed bright HC _ { 5 } N emission . From a non-LTE analysis of the IRAM-30m data , the c–C _ { 3 } H _ { 2 } gas has an average temperature of \sim 40 K , a H _ { 2 } density of \sim 3 \times 10 ^ { 5 } Â cm ^ { -3 } , and a c–C _ { 3 } H _ { 2 } abundance relative to H _ { 2 } of ( 7 \pm 1 ) \times 10 ^ { -12 } . In addition , the NOEMA observations provide no sign of significant c–C _ { 3 } H _ { 2 } excitation temperature gradients across the region ( about 3-4 beams ) , with T _ { ex } in the range 8 \pm 3 up to 16 \pm 7Â K. We thus infer that our observations are inconsistent with a physical interaction of the OMC–2Â FIR 4 envelope with the outflow arising from OMC–2Â FIR 3 , as claimed by previous studies . The comparison of the measured c–C _ { 3 } H _ { 2 } abundance with the predictions from an astrochemical PDR model indicates that OMC–2Â FIR 4 is irradiated by a FUV field \sim 1000 times larger than the interstellar one , and by a flux of ionising particles \sim 4000 times larger than the canonical value of 1 \times 10 ^ { -17 } Â s ^ { -1 } from the Galaxy cosmic rays , which is consistent with our previous HC _ { 5 } N observations . This provides an important and independent confirmation of other studies that one or more sources inside the OMC–2Â FIR 4 region emit energetic ( \geq 10 Â MeV ) particles .