碘、碘离子和碘三离子的紫外吸收光谱

Ultraviolet Absorption Spectra of Iodine, Iodide Ion and Triiodide Ion

研究了碘I2、碘离子I-和碘三离子I-3水溶液的紫外吸收光谱,测定了三种型体的摩尔吸光系数。I2水溶液在203nm呈现一吸收峰,摩尔吸光系数为196×104L·mol-1·cm-1;I-水溶液在193和226nm呈现双吸收峰,摩尔吸光系数分别为142×104和134×104L·mol-1·cm-1;当I2水溶液与KI溶液混合时,在288和350nm出现两个吸收峰,表明I-3的形成。利用饱和法测得I-3在288和350nm处的摩尔吸光系数分别为352×104和232×104L·mol-1·cm-1。

Ultraviolet absorption spectra of iodine I-2, iodide ion I- and triiodide ion I-3(-) were studied, and molar absorptivities of these species were determined. Absorption spectrum Of 12 aqueous solution appears as an absorption peak at 203 rim with a molar absorptivity of 1.96 X 10(4 .) L (.) mol(-1 .) cm(-1). Absorption speartrum of I- appears as two absorption peaks at 193 and 226 nm with molar absorptivities of 1.42 X 10(4) and 1.34 X 10(4) L (.) mol(-1) (.) cm(-1), respectively. When I-2 aqueous solution is mixed with KI solution, two absorption peaks appear at 288 and 350 rim, respectively, indicating the formation of I-3(-). Using saturation method, molar absorptivities of 13 at 288 and 350 nm were determined to be 3.52 X 10(4) and 2.32 X 10(4) L (.) mol(-1) (.) cm(-1), respectively.