Description_x000D_ Application_x000D_ 5-Iodo-2′-deoxycytidine (5-iododeoxycytidine) is used in the construction of DNA oligomers to enable structural studies and photoactivated cross-linking. 5-Iodo-2′-deoxycytidine is used in the synthesis of other modified nucleosides, such as 5-ethynylferrocenyl-2′-deoxycytidine used in semiconductor electrodes and 10-(2-deoxyβ-D-ribofuranosyl)pyrimido[4′,5′:4,5]pyrimido[1,6-a]indole-6,9(7H)-dione (dCPPI).