by Alexandra Velian, and Christopher C. Cummins Synthesis and characterization of P2N3−: An aromatic ion composed of phosphorus and nitrogen by Alexandra Velian, and Christopher C. Cummins Science Volume 348(6238):1001-1004 May 29, 2015 Published by AAAS

Fig. 1 Solid-state molecular structure of [Na-kryptofix-221] [P2N3]. Solid-state molecular structure of [Na-kryptofix-221] [P2N3]. Hydrogen atoms are omitted for clarity; the ellipsoids are plotted at the 50% probability level. The P2N3− unit is disordered over two positions with occupancies of 92% (major component) and 8% (minor component), respectively (inset A). Selected interatomic distances and angles: (major component) N2-N1, 1.326 ± 0.002 Å; N1-P1, 1.677 ± 0.002 Å; P1-P2, 2.069 ± 0.001 Å; P2-N3, 1.680 ± 0.002 Å; N3-N2, 1.310 ± 0.002 Å; P1-P2-N3, 93.17° ± 0.08°; P2-N3-N2, 117.7° ± 0.2°; N1-N2-N3, 118.5° ± 0.2°; (minor component) N3B-N2B, 1.32 ± 0.03 Å; N2B-N1B, 1.32 ± 0.02 Å; N1B-P1B, 1.64 ± 0.02 Å; P1B-P2B, 2.08 ± 0.02 Å; P2B-N3B, 1.69 ± 0.02 Å. A model of P2N3− anion was optimized using DFT methods (27, 32); selected interatomic distances and angles: P-P, 2.07 Å; P-N, 1.69 Å; N-N, 1.31 Å; P-P-N, 93°; P-N-N, 117°; N-N-N, 120°. Alexandra Velian, and Christopher C. Cummins Science 2015;348:1001-1004 Published by AAAS

Fig. 2 Characterization of the [Na-kryptofix-221] [P2 15NN2] salt. Characterization of the [Na-kryptofix-221] [P215NN2] salt. (A) Preparation by thermolysis of P2A2 in the presence of [Na-kryptofix-221] [15NN2]. (B and C) Experimental (up) and simulated (down) 15N NMR and 31P NMR spectra, respectively, of the [P215NN2]− ion. (D and E) IR and Raman vibrational spectra, respectively, of solid [Na-kryptofix-221] [P2N3] and [Na-kryptofix-221] [P215NN2]. Alexandra Velian, and Christopher C. Cummins Science 2015;348:1001-1004 Published by AAAS

Fig. 3 Theoretical bonding analysis. Theoretical bonding analysis. Natural resonance theory (NRT) (33) resonance weights (top) calculated for the diphosphatriazolate anion, P2N3− (34, 35). The topology of the Laplacian distribution of charge density (bottom) in the plane of the P2N3− anion is shown with regions of charge depletion in solid curves and those of charge concentration in dashed curves. Bond paths, bond and ring critical points, and atomic basin paths are also depicted (21). Alexandra Velian, and Christopher C. Cummins Science 2015;348:1001-1004 Published by AAAS

Fig. 4 Probing aromaticity. Probing aromaticity. Plotted is NICS(z) versus r (Å) (27) for Cp−, P2N3−, P5−, N5−, and N2S32+. Alexandra Velian, and Christopher C. Cummins Science 2015;348:1001-1004 Published by AAAS