876 [MnW(C12HloP)2(C5H5)(CO)6] C6 0.9428 (7) 0.4954 (7) 0.1420 (4) 0.057 (4) 06 0.9719 (6) 0.4469 (6) 0.1550 (4) 0.104 (4) Cll 0.7418 (6) 0.5113 (6) 0.0732 (3) 0.039 (3) C12 0.6844 (7) 0.5248 (7) 0.0524 (3) 0.051 (3) C13 0.6495 (8) 0.4649 (9) 0.0373 (3) 0.063 (4) C14 0.6713 (9) 0.3957 (7) 0.0430 (3) 0.062 (4) C15 0.7289 (8) 0.3854 (7) 0.0641 (3) 0.060 (4) C16 0.7630 (6) 0.4424 (6) 0.0790 (3) 0.043 (3) C21 0.7842 (7) 0.6543 (7) 0.0606 (3) 0.049 (3) C22 0.7611 (7) 0.7246 (7) 0.0629 (3) 0.051 (3) C23 0.7745 (8) 0.7729 (8) 0.0377 (4) 0.065 (4) C24 0.8094 (9) 0.7539 (9) 0.0096 (4) 0.073 (5) C25 0.8311 (8) 0.6823 (9) 0.0065 (3) 0.068 (4) C26 0.8195 (8) 0.6334 (7) 0.0320 (3) 0.055 (4) C31 0.8481 (7) 0.6174 (7) 0.2031 (3) 0.043 (3) C32 0.8200 (8) 0.6802 (6) 0.2158 (3) 0.050 (3) C33 0.8530 (9) 0.7141 (8) 0.2423 (3) 0.063 (4) C34 0.9141 (8) 0.6875 (8) 0.2566 (3) 0.059 (4) C35 0.9407 (8) 0.6254 (8) 0.2450 (3) 0.064 (4) C36 0.9074 (7) 0.5897 (7) 0.2181 (3) 0.056 (4) C41 0.7901 (6) 0.4844 (6) 0.1854 (3) 0.040 (3) C42 0.7526 (7) 0.4838 (7) 0.2142 (3) 0.047 (3) C43 0.7287 (8) 0.4225 (8) 0.2298 (4) 0.061 (4) C44 .0.7446 (9) 0.3557 (8) 0.2139 (5) 0.075 (5) C45 0.7843 (8) 0.3560 (8) 0.1843 (4) 0.067 (4) C46 0.8041 (7) 0.4197 (6) 0.1698 (4) 0.052 (4) C51 0.9722 (7) 0.6598 (6) 0.0897 (3) 0.083 (6) C52 1.0170 (6) 0.6257 (6) 0.1130 (4) 0.075 (5) C53 0.9944 (6) 0.6457 (6) 0.1451 (3) 0.070 (4) C54 0.9356 (6) 0.6922 (5) 0.1417 (3) 0.056 (4) C55 0.9219 (6) 0.7009 (6) 0.1075 (3) 0.071 (5) Sheldrick, G. M. (1993). SHELXL93. Program for Crystal Structure Re- finement. Univ. of Grttingen, Germany. Shyu, S.-G., Calligaris, M., Nardin, G. & Wojcicki, A. (1987). J. Am. Chem. Soc. 109, 3617-3625. Targos, T. S., Rosen, R. P., Whittle, R. R. & Geoffroy, G. L. (1985). Inorg. Chem. 24, 1375-1379. Acta Cryst. (1994). C50, 876-879 Effects of Halogen Substitution in Nucleic Acid Components. Structure of Sodium 5-Bromocytidine 5'-Phosphate Hydrate SHARMILA S. MANDE,* T. P. SESHADRI AND M. A. VISWAMITRA Department of Physics, Indian Institute of Science, Bangalore 560 012, India (Received 20 March 1992; accepted 8 September 1993) Table 2. Selected geometric parameters (A, o) Wl--Cp 2.002 (10) MnI--P1 2.384 (4) W1--P1 2.539 (3) Mnl--P2 Z390 (4) W1--P2 2.550 (3) C6--W1--C5 81.1 (6) Cp--WI--C5 116.6 (6) C6--WI--P1 125.7 (4) Cp--W1--C6 115.9 (6) C5--W1--P1 79.7 (4) P1--Mnl--P2 74.98 (12) Cp--WI--P1 118.1 (4) C21--P1--Cll 99.8 (6) C6--W1--P2 82.4 (5) Mnl--PI--WI 105.47 (12) C5--W1--P2 126.1 (4) C41--P2--C31 98.5 (5) Cp--W1--P2 116.9 (4) Mnl--P2--W1 104.95 (12) PI--WI--P2 69.64 (10) Program(s) used to solve structure: SHELXTL-Plus (Sheldrick, 1991). Program(s) used to refine structure: SHELXL93 (Sheld- rick, 1993). Lists of structure factors, anisotropic displacement parameters and H-atom coordinates have been deposited with the IUCr (Reference: NA1073). Copies may be obtained through The Managing Editor, Inter- national Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England. References Breen, M. J., Geoffroy, G. L., Rheingold, A. L. & Fultz, W. C. (1983). J. Am. Chem. Soc. 105, 1069-1070. Breen, M. J., Shulmart, P. M., Geoffroy, G. L., Rheingold, A. L. & Fultz, W. C. (1984). Organometallics, 3, 782-793. FlSrke, U. & Hanpt, H.-J. (1993). Acta Cryst. C49, 533-535. Fl6rke, U. & Haupt, H.-J. (1994). Acta Cryst. C50, 378-380. Masuda, H., Taga, T., Machida, K. & Kawarnura, T. (1987). J. Organomet. Chem. 331, 239-245. Mercer, W. C., Geoffroy, G. L. & Rheingold, A. L. (1984). Organomet- allics, 4, 1418-1425. Morrison, E. D., Harley, A. D., MarceUi, M. A., Geoffroy, G. L., Rbein- gold, A. L. & Fultz, W. C. (1984). Organometallics, 3, 1407-1413. Sheldrick, G. M. (1991). SHELXTL-Plus. Release 4.1. Siemens Analyt- ical X-ray Instruments Inc., Madison, Wisconsin, USA. Abstract The conformation of 5-bromocytidine 5'-mono- phosphate in the title compound, Na+.C9HIIBrN3OsP-.1.25H20, is anti, C(3")-endo and gauche-gauche, similar to that in analogous non- halogenated nucleosides/nucleotides. The Na ion coordinates directly with phosphate O atoms and base atoms. Br is not involved in any stacking inter- action. Comment Although there have been a number of crystallo- graphic studies on halogenated nucleosides, only a few structures of halogenated nucleotides have been reported. We report here the crystal structure of the sodium salt of 5-bromocytidine monophosphate (I); this is the first halogenated pyrimidine mononucleo- tide to be determined. Cytosine with bulky substit- Br O.aP ~ Q o . OH HO 0 (I) uents such as bromine and iodine at the 5 position is found to be a good substrate for human DNA (cytosine-5) methyltransferase (Hardy, Barker, Newman, Sowers, Goodman & Smith, 1987). The presence of monovalent sodium in the present struc- ture is also of interest in view of the fact that earlier © 1994 International Union of Crystallography Printed in Great Britain - all rights reserved Acta Crystallographica Section C ISSN 0108-2701 ©1994