Table 3. T_m and Thermodynamic Parameter Data for Partially Acetylated-RNA Duplexes.

Experiments were performed in a 10 mM Na₂HPO₄, 0.5 mM Na₂EDTA buffer (pH7) containing 1 M NaCl and using 2.5 μM of each complementary strand over a temperature range of 30–90 °C. Data is an average of three heat–cool cycles. Error for T_m values represent standard deviations of 6 values and are ±0.8 °C. Errors for thermodynamic data represent standard deviations of 6 values and are ±7.4% for ΔH°, within ±8.5% for ΔS° and within ±3.1 kJmol^–1 for ΔG°₃₇. Nonacetylated oligonucleotides were either synthesized using standard procedures or purchased in HPLC-purified Na⁺ form. Underlined nucleotides denote overhanging sequence, subscripts denote site of acetylation or linkage isomerism, green denotes site of 3′-5′ natural linkage and red denotes site of 2′-5′ unnatural linkage isomerism. See Figure S3 (Supporting Information) for UV melting curves.