Instituto de Química Médica (CSIC), Juan de la Cierva, 3, 28006, Madrid, Spain.
Doctoral School, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Sci Rep. 2023 Feb 10;13(1):2407. doi: 10.1038/s41598-023-29336-y.
The reactivity of a BP-doped hexa-cata-hexabenzocoronene, as a model of nanographene (BP-NG), towards carbon dioxide was studied at the DFT M06-2X/6-311++G(3df,3pd)//M06-2X/6-31+G* level of theory. This compound can be classified as a poly-cyclic poly-Frustrated Lewis Pair (FLP) system, as it presents more than one Lewis Acid/Lewis Base pair on its surface, making the capture of several carbon dioxide molecules possible. Two scenarios were considered to fully characterize the capture of CO by this multi-FLP system: (i) fixation of three CO molecules sequentially one by one; and (ii) simultaneous contact of three CO molecules with the BP-NG surface. The resulting adducts were analyzed as function of activation barriers and the relative stability of the CO capture. A cooperativity effect due to the π-delocalization of the hexa-cata-hexabenzocoronene is observed. The fixation of a CO molecule modifies the electronic properties. It enhances the capture of additional CO molecules by changing the acidy and basicity of the rest of the boron and phosphorus atoms in the BP-NG system.
采用 DFT M06-2X/6-311++G(3df,3pd)//M06-2X/6-31+G* 理论水平研究了 BP 掺杂的六并六苯并蔻（作为纳米石墨烯（BP-NG）的模型）与二氧化碳的反应性。该化合物可归类为多环多受阻路易斯对（FLP）体系，因为其表面存在不止一对路易斯酸/路易斯碱对，从而有可能捕获多个二氧化碳分子。考虑了两种情况来充分描述该多 FLP 体系对 CO 的捕获：（i）顺序固定三个 CO 分子；和（ii）同时将三个 CO 分子与 BP-NG 表面接触。对得到的加合物进行了分析，以研究 CO 捕获的活化势垒和相对稳定性。观察到由于六并六苯并蔻的π离域作用而产生的协同效应。CO 分子的固定会改变电子性质，从而通过改变 BP-NG 体系中其余硼和磷原子的酸度和碱度，增强对额外 CO 分子的捕获。
