Modes Cytosine Thiocytosine Assignments Cyt Cyt+ Cyt- TCyt TCyt+ TCyt- Cal Exp[9] Cal Cal Exp[11] Cal ν1 128 (2,0) 0.75 123(R,vvw) 98 (11,1) 0.75 130 (152,68005) 0.23 111 (0, 0) 0.75 98(R,vw) 147 (4,1) 0.64 89 (1,950) 0.35 φ (ring)” ν2 180 (171,3) 0.20 162 (R,vw) 477 (154, 0) 0.75 555 (1629,512264) 0.25 50 (188, 1) 0.27 50( R,w)   500 (159,1) 0.71 803 (285,3206) 0.27 ω (NH2)’ ν3 200 (55, 0) 0.35   187 (1,0) 0.75 190 (21, 2638) 0.747 185 (23, 0) 0.75   105 (14, 6) 0.68 146 (17, 125) 0.46 φ (ring)” ν4 358 (3,0) 0.65 356 (R,vw) 334 (35,156) 0.749 364 (14,12046) 0.40 438 (3, 3) 0.62 434(IR,ms) 432 (R,w) 421 (7,8) 0.37 424 (7,8) 0.62 β (C-NH2) ν5 395 (21,1) 0.74 421(IR,w ) 400(R,w) 386 (5,1 ) 0.75 312 (1154,404838) 0.23 404 (14, 1) 0.75 422(IR,s) 423(R,w) 398 (8,4) 0.65 305 (27,3537) 0.31 φ (ring)” ν6 525 (11,0) 0.73 520 (IR,sh) 517(R,w) 641 (36, 0) 0.75 329 (496,190998) 0.34 538 (9, 0) 0.63 527 (IR,vs)   594 (87,0) 0.43 205 (27,148) 0.67 θ (NH2)’ ν7 533 (3,2) 0.55 533(IR,m) 533 (R,m) 520 (1 ,46) 0.75 500 (2118,525975) 0.22 269 (1, 3) 0.75   213 (0,3) 0.50 255 (10,1153) 0.31 β (CO/S)’ ν8 545 (3,3) 0.44 549(IR,mw) 546(R,mw) 537 (0, 59) 0.54 534 (15,10053) 0.39 555 (1, 7) 0.17 551(IR,s) 550(R,mw) 557 (1,14) 0.20 534 (14,45) 0.50 α (ring)’ ν9 579 (3,7) 0.38 566 (IR ,w) 568(R,mw) 571 (18,10) 0.58 578 (70,14401) 0.57 470 (6,17) 0.21 456(IR,vs) 452(R,s) 436 (1,1) 0.15 452 (27,12) 0.74 α (ring)’ ν10 619 (66,0) 0.16 600(IR,ms) 597(R,vw) 708 (51,0) 0.75 490 (896,48474) 0.26 658 (43, 1) 0.75 652(IR,ms) 659(R,vw) 555 (47,15) 0.65 464 (64,1783) 0.24 γ (N1H)’ ν11 723 (30,0) 0.55 701(IR,sh) 704(R,vw) 845 (9, 1) 0.75 802 (175,126126) 0.43 730 (14,2) 0.75 724(IR,mw) 718(R,vs) 823 (35,0) 0.69 758 (50,1690) 0.29 γ (C5H)’ ν12 762 (9,5) 0.06 760(IR,msh) 764(R,w) 555 (38,0) 0.75 655 (1120,15899) 0.33 768 (31, 3 ) 0.74 752(IR,ms) 755(R,vw) 740 (0,1) 0.68 557 (28,1513) 0.28 γ (C-NH2)” ν13 766 (5,2) 0.06 782(IRmw) 782(R,mw) 721 (83,468) 0.47 742 (440,73423) 0.23 716 (0, 21) 0.06 710(R,ssh)   715 (4,11) 0.14 701 (11,2163) 0.27 ν (ring)’ ν14 774 (46,1) 0.41 793(IR,ms) 792 (R,s) 737 (75, 1) 0.75 767 (21,6974) 0.55 651 (15, 0) 0.73   625 (2,5) 0.73 669 (9,127) 0.34 γ (CO/S)” ν15 919 (5,3) 0.51 894(R,vw) 922 (2,37) 0.71 931 (234,7728) 0.67 920 (11, 3) 0.38 930(IR,ms) 932(R,mw) 929 (1,26) 0.15 908 (26,405) 0.26 ν (ring)’ ν16 957 (1,1) 0.71 966(IR,w) 971(R,ssh) 991 (0,1) 0.75 595 (234,137124) 0.65 960 (0, 1) 0.75 967(IR,vw) 965(R,mw) 979 (0,0) 0.73 314 (125,6095) 0.28 γ (C6H)’ ν17 986 (1,3) 0.25 994(IR,ms) 990(R,ms) 947 (128,166) 0.75 1000 (9, 4882) 0.30 976 (24,7) 0.19  983(IR,mw) 971(R,ms) 985 (2,4) 0.12 958 (5,68) 0.15 α (ring)’ ν18 1084 (47,3) 0.23   999 (80,356) 0.62 1109 (328,52914) 0.24 1069 (29, 5) 0.10   1065 (11,1) 0.66 1121 (10,327) 0.08 ρ (NH2)’ ν19 1125 (3,8) 0.30 1100(IR,w) 1108(R,vw) 1135 (0,37) 0.66 1171 (729,461449) 0.32 1109 (100, 4) 0.73 1098(IR,ms) 104(R,ms) 1108 (10,11) 0.25 987 (48,10746) 0.26 β (CH)’ ν20 1214 (49,10) 0.51 - 1257 (43, 479) 0.74 1438 (724,59563) 0.21 1231 (46, 5) 0.43 1235(IR,s) 1249(R,mw) 1243 (57,5) 0.31 1186 (109,3146) 0.20 β (NH)’ ν21 1254 (31,3) 0.12 1236(IR,mw) 1247(R,w) 1176 (134,314) 0.73 969 (4096, 0) 0.24 1318 (140, 61) 0.10 1302(IR,vs) 301(R,vs) 1497 (45,7) 0.11 1324 (224,385) 0.67 ν (ring)’ ν22 1354 (56,6) 0.09 1364(IR,ms) 1361(R,w) 1365 (46,36) 0.61 1420 (812, 33834) 0.21 1371 (33, 4) 0.46 1368(IR,ms) 1370 (R,ms) 1384 (48,5) 0.72 1365 (2, 3289) 0.29 β (CH)’ ν23 1442 (87,7) 0.19 1465(IR,vs ) 1462(R,w) 1393 (64, 282) 0.65 1203 (358, 82892) 0.18 1461 (45,10) 0.42 1460 (IR,s) 463(R,ms) 1416 (37,6) 0.49 1495 (276,136) 0.27 ν (ring)’ ν24 1499 (155,6) 0.31 1505(IR,s) 1498(R,w) 1516 (91, 8) 0.15 1306 (1109,58525) 0.14 1496 (321,9) 0.14 1505 (IR,sh) 495(R,w) 1541 (170,9) 0.67 1263 (42,146) 0.23 ν (C-NH2)’ ν25 1564 (169,22) 0.34 1538(IR,ms) 1533(R,ssh) 1555 (29, 420) 0.75 1377 (5367,895702) 0.24 1576 (527, 28) 0.11 1580(IR,vvs) 1582(R,ms) 1601 (461,33) 0.69 1562 (279,47006) 0.23 ν (ring)’ ν26 1632 (140,9) 0.17 1615(IR,vs ) 1612(R,w) 1679 (493, 15) 0.63 1589 (1748, 80132) 0.55 1636 (73, 5) 0.22 1630 (R,w) 1665 (3,12) 0.17 1614 (25,2902) 0.37 σ (NH2)’ ν27 1683 (508,13) 0.11 1662(IR,vvs) 1653(R,ms) 1609 (133,60) 0.73 1554 (2301, 48957) 0.15 1670 (668, 22) 0.30 1645(IR,vvs) 669(R,ms) 1690 (739,16) 0.18 1452 (377,2197)0.43 ν (ring)’ ν28 1769 (780,7) 0.29 - 1426 (32,287) 0.68 1668 (1743, 256147) 0.24 1142 (150, 9) 0.21 1163(IR,ssh) 1167(R,sh) 1205 (83,6) 0.30 1063 (85,919) 0.33 ν (CO/S)’ ν29 3193 (3,81) 0.49 3169(IR,s) 3176(R,ms) 3207 (5, 77) 0.69 3183 (1104, 90876) 0.35 3200 (2, 76) 0.57 3063(IR,ssh) 061(R,vs) 3230 (9,141) 0.17 3189 (46,4664) 0.74 ν (CH)’ ν30 3218 (2,128) 0.19 3230 (R,vvs) 3217 (12, 124) 0.15 3149 (132, 100464) 0.36 3221 (1, 162) 0.20 3094(IR,vs) 3090(R,vs) 3216 (4,59) 0.61 3152 (22,1241) 0.38 ν (CH)’ ν31 3601 (93,149) 0.13 3380(IR,vs) 3354(R,vvs) 3564 (192,349) 0.13 3406 (10540,40051)0.12 3605 (47, 253) 0.16 3312(IR,s) 320(R,ms) 3569 (330,83) 0.14 3475 (137,100636)0.28 νs (NH2)’ ν32 3618 (69,138) 0.22 - 3536 (319,74) 0.40 3615 (1149,331894)0.27 3600 (135,14) 0.35   3578 (54,136) 0.18 3637 (29,1122) 0.24 ν (N1H)’ ν33 3734 (51,8) 0.70 - 3689 (90,19) 0.48 3556 (206,129271) 0.44 3740 (61, 68) 0.64 3334(IR,vs) 34(R,ssh) 3694 (109,53) 0.68 3588 (16,15900) 0.36 νas (NH2)’

[a] The first and second numbers within each bracket represent IR intensity(IR) and Raman activity (R) while the numbers above and below bracket represent the corresponding calculated frequency and depolarization ratio of the Raman band respectively. [b] ν=stretching mode, α=deformation mode, φ=out-of-plane ring deformation mode, β=in-plane bending mode, γ=out-of-plane bending mode, δ=deformation mode, ρ ║=parallel rocking mode, ρ +=perpendicular rocking mode, τ=torsion mode [c] vw: very-weak, w: weak, mw: medium-weak, ms: medium-strong, sh: shoulder, msh: medium-shoulder, ssh: strong shoulder, s: strong, vs: very-strong, vvs: very- very strong.

Table 3: Experimental and Calculated Vibrational frequencies for Cyt, TCyt and their cations and anions.