Supporting Information: Planar Pentacoordinate Carbon in CAl 5 + : A Global Minimum Yong Pei, Wei An, Keigo Ito, Paul von Ragué Schleyer, Xiao Cheng Zeng * Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588 Center for Computational Chemistry, University of Georgia, Athens, Georgia, 30602 Email: xczeng@phase2.unl.edu Part I. Isomer structures and their relative energies: CAl 5 +, CSi 5 2-, CBe 5, CP 5 3+, and CB 5. Part II. PpC contained structures CAl + 5, CSi 2-5, CBe 5, CP 3+ 5, CB 5, CSi 4 P - (Ref. 27b), and CSi 3 P 2 (Ref. 27b). Part III. Figure S1: Calculated IR spectrum for the 2D ppc structure of CAl 5 + and vibration frequencies. Part IV. Complete Reference 48 S1
Part I. Isomer structures and their relative energies: CAl 5 +, CSi 5 2-, CBe 5, CP 5 3+, and CB 5. The planar pentacoordinate carbon structures are highlighted in red. Top eight isomer structures and relative energies (kcal/mol, at 0 K) of CAl + 5. (The B3LYP/aug-cc-pVTZ and CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ relative energies are in black and red, respectively). All structures are confirmed as stable minima by frequency calculations. D 5h, 1 A 1 C 2v, 1 A 1 C 3v, 1 A 1 C 2v, 1 A 1 C 2v, 1 A 1 (0.00) (1.00) (3.96) (3.36) (7.09) (0.00) (3.80) (5.00) (9.41) (12.34) C s, 1 A C 2v, 3 A 1 C 2v, 1 A 1 (10.15) (11.78) (16.11) Top eight isomer structures and relative energies (kcal/mol, at 0 K) of CSi 5 2-. S2
(B3LYP/aug-cc-pVTZ energies). All structures are confirmed as stable minima by frequency calculations. 0.00 1.31 1.77 C 2, 1 A C 2v, 1 A 1 C 1, 1 A 5.75 8.93 14.12 C s, 1 A C 1, 1 A C s, 1 A 14.57 15.27 D 5h, 1 A 1 C s, 1 A Top eleven isomer structures and relative energies (kcal/mol, at 0 K) of CBe 5. S3
(B3LYP/aug-cc-pVTZ energies). All structures are confirmed as stable minima by frequency calculations. C 2v, 1 A 1 C s, 3 A C s, 1 A C s, 1 A 0.00 1.32 5.48 7.07 C s, 3 A C 1, 1 A C s, 1 A C s, 1 A 7.88 8.46 9.13 9.26 C 2v, 3 A 1 C s, 1 A D 5h, 1 A 1 11.13 12.43 19.82 Top eight isomer structures and relative energies (kcal/mol, at 0 K) of CP 5 3+. S4
(B3LYP/aug-cc-pVTZ energies). All structures are confirmed as stable minima by frequency calculations. C 2, 1 A C s, 1 A C s, 1 A C s, 1 A 0.00 17.22 32.11 34.71 C s, 1 A C 1, 1 A C 2v, 1 A 1 D 5h, 1 A 1 35.50 38.00 41.08 63.86 S5
Top eight isomer structures and relative energies (kcal/mol, at 0 K) of CB 5. (B3LYP/aug-cc-pVTZ energies). All structures are confirmed as stable minima by frequency calculations. C 2v, 2 A 1 C s, 2 A C s, 2 A 0.00 7.06 28.93 C s, 2 A C s, 2 A C s, 2 A 37.45 38.79 43.13 C s, 2 A C 2v, 2 A 1 44.48 44.59 S6
Part II. PpC contained local minimum structures CAl 5 +, CSi 5 2-, CBe 5, CP 5 3+, CB 5, CSi 4 P - (Ref. 27b), and CSi 3 P 2 (Ref. 27b). CAl 5 + D 5h E Tot. = -1250.1134197 a.u. (B3LYP/aug-cc-pVTZ) -1247.770025 a.u. (CCSD(T)/aug-cc-pVTZ//MP2/ aug-cc-pvtz) ZPE = 5.19766 kcal/mol HOMO-LUMO Gap = 2.82 ev NImag = 0 ν Min. = 67.8 cm 1 Cartesian Coordinate (Å) Al 0.000000 2.105660 0.000000 Al 2.002602 0.650685 0.000000 Al -1.237676-1.703515 0.000000 Al 1.237676-1.703515 0.000000 Al -2.002602 0.650685 0.000000 C 0.000000 0.000000 0.000000 S7
CSi 5 D 5h E Tot. = -1485.58060764 a.u. ZPE = 5.60 kcal/mol HOMO-LUMO Gap = 1.63 ev NImag = 0 ν Min. = 140.1 cm 1 Cartesian Coordinate (Å) Si 0.000000 2.003105 0.000000 Si 1.905066 0.618994 0.000000 Si 1.177396-1.620546 0.000000 Si -1.177396-1.620546 0.000000 Si -1.905066 0.618994 0.000000 C 0.000000 0.000000 0.000000 S8
CB 5 C 2v E Tot. = 162.05064260 a.u. (B3LYP/aug-cc-pVTZ) ZPE = 12.10 kcal/mol HOMO-LUMO Gap = 2.51 ev NImag = 0 ν Min. = 114.3 cm 1 Cartesian Coordinate (Å) B 0.000000 1.468705 0.980024 B 0.000000-1.468705 0.980024 B 0.000000-1.399552-0.559078 B 0.000000 1.399552-0.559078 C 0.000000 0.000000 0.345496 B 0.000000 0.000000-1.256487 S9
CP 3+ 5 D 5h E Tot. = 1743.511666 a.u. (B3LYP/aug-cc-pVTZ) ZPE = 5.63 kcal/mol HOMO-LUMO Gap = 3.95 ev NImag = 0 ν Min. = 142.8 cm 1 Cartesian Coordinate (Å) C 0.000000 0.000000 0.000000 P 0.000000 1.909521 0.000000 P 1.816062 0.590074 0.000000 P 1.122388-1.544835 0.000000 P -1.122388-1.544835 0.000000 P -1.816062 0.590074 0.000000 S10
CBe 5 D 5h E Tot. = -111.650965437 a.u. (B3LYP/aug-cc-pVTZ) ZPE = 8.02118 kcal/mol HOMO-LUMO Gap = 1.32 ev NImag = 0 ν Min. = 196.2 cm 1 Cartesian Coordinate (Å) Be 1.600069 0.605226 0.023391 Be -1.436142-0.071508-0.924214 Be 0.270695 0.847245-1.459595 Be -1.165376-0.883517 0.887961 Be 0.725001-0.495359 1.465305 C 0.003654-0.001058 0.004872 S11
CSi 4 P C 2v E Tot. = 1537.54345 a.u. ZPE = 6.10 kcal/mol HOMO-LUMO Gap = 2.54 ev NImag = 0 ν Min. = 132.6 cm 1 Cartesian Coordinate (Å) C -0.10265 0.00000 0.00000 P 1.84154 0.00000 0.00000 Si 0.62500 1.91367 0.00000 Si 0.62500-1.91367 0.00000 Si -1.58954 1.20610 0.00000 Si -1.58954-1.20610 0.00000 S12
CSi 3 P 2 C 2v E Tot. = 1589.34615 a.u. ZPE = 6.36 kcal/mol HOMO-LUMO Gap = 3.11 ev NImag = 0 ν Min. = 122.1 cm 1 Cartesian Coordinate (Å) C -0.16908 0.00000 0.00000 P 0.60892-1.69489 0.00000 P 0.60892 1.69489 0.00000 Si 2.08106 0.00000 0.00000 Si -1.65671-1.18735 0.00000 Si -1.65671 1.18735 0.00000 S13
CSi 3 P 2 C 2v E Tot. = 1589.33894 a.u. ZPE = 6.36 kcal/mol HOMO-LUMO Gap = 3.47 ev NImag = 0 ν Min. = 126.6 cm 1 Cartesian Coordinate (Å) C 0.15440 0.00000 0.00000 Si 0.56414-1.91457 0.00000 Si 0.56414 1.91457 0.00000 Si 2.01550 0.00000 0.00000 P -1.49798-1.10839 0.00000 P -1.49798 1.10839 0.00000 S14
Part III. Figure S1. Calculated IR spectrum for the 2D ppc structure of CAl 5 + and vibration frequencies. Infrared Spectrum 750 627.74 cm -1 600 Intensity 450 300 150 0 0 100 200 300 400 500 600 700 800 Frequency (cm-1) v 1 (a 1 ) 370.4 cm -1 v 2 (a 2 ) 208.6 cm -1 v 3 (e 1 ) 627.7 cm -1 v 4 (e 1 ) 300.8 cm -1 v 5 (e 2 ) 406.8 cm -1 v 6 (e 1 ) 79.1 cm -1 v 7 (e 2 ) 69.4 cm -1 S15
Part IV. Complete Reference 48 Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, Jr., J. A.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; and Pople, J. A. Gaussian 03, Revision C.02, Gaussian, Inc., Wallingford CT, 2004. S16