Silvi Serena, Constable Edwin C, Housecroft Catherine E, Beves Jonathon E, Dunphy Emma L, Tomasulo Massimiliano, Raymo Françisco M, Credi Alberto
Dipartimento di Chimica G. Ciamician, Università di Bologna via Selmi 2, 40126 Bologna, Italy.
Chemistry. 2009;15(1):178-85. doi: 10.1002/chem.200801645.
Molecular logic gates process physical or chemical "inputs" to generate "outputs" based on a set of logical operators. We report the design and operation of a chemical ensemble in solution that behaves as integrated AND, OR, and XNOR gates with optical input and output signals. The ensemble is composed of a reversible merocyanine-type photoacid and a ruthenium polypyridine complex that functions as a pH-controlled three-state luminescent switch. The light-triggered release of protons from the photoacid is used to control the state of the transition-metal complex. Therefore, the two molecular switching devices communicate with one another through the exchange of ionic signals. By means of such a double (optical-chemical-optical) signal-transduction mechanism, inputs of violet light modulate a luminescence output in the red/far-red region of the visible spectrum. Nondestructive reading is guaranteed because the green light used for excitation in the photoluminescence experiments does not affect the state of the gate. The reset is thermally driven and, thus, does not involve the addition of chemicals and accumulation of byproducts. Owing to its reversibility and stability, this molecular device can afford many cycles of digital operation.
分子逻辑门基于一组逻辑运算符处理物理或化学“输入”以生成“输出”。我们报道了一种溶液中的化学组合体系的设计与运行情况，该体系表现为具有光输入和输出信号的集成与门、或门和同或门。该组合体系由一种可逆的部花青类光酸和一种钌多吡啶配合物组成，后者用作受pH控制的三态发光开关。光酸中质子的光触发释放用于控制过渡金属配合物的状态。因此，这两个分子开关装置通过离子信号的交换相互通信。借助这种双重（光 - 化学 - 光）信号转导机制，紫光输入可调节可见光谱红/远红区域的发光输出。由于用于光致发光实验激发的绿光不会影响门的状态，所以保证了无损读取。复位是由热驱动的，因此不涉及化学物质的添加和副产物的积累。由于其可逆性和稳定性，这种分子器件可以进行许多轮数字操作。
