Icosahedral carboranes, C₂B₁₀H₁₂, have long been considered to be aromatic but the extent of conjugation between these clusters and their substituents is still being debated. m- and p-Carboranes are compared with m- and p-phenylenes as conjugated bridges in optical functional chromophores with a donor and an acceptor as substituents here. The absorption and fluorescence data for both carboranes from experimental techniques (including femtosecond transient absorption, time-resolved fluorescence and broadband fluorescence upconversion) show that the absorption and emission processes involve strong intramolecular charge transfer between the donor and acceptor substituents via the carborane cluster. From quantum chemical calculations on these carborane systems, the charge transfer process depends on the relative torsional angles of the donor and acceptor groups where an overlap between the two frontier orbitals exists in the bridging carborane cluster.

二十面体碳硼烷，C ₂ B ₁₀ H ₁₂ ，长期以来一直被认为是芳香族的，但这些簇及其取代基之间的共轭程度仍在争论中。此处将间碳硼烷和对碳硼烷与间亚苯基和对亚苯基作为光学功能发色团中的共轭桥进行比较，其中供体和受体作为取代基。来自实验技术（包括飞秒瞬态吸收、时间分辨荧光和宽带荧光上转换）的两种碳硼烷的吸收和荧光数据表明，吸收和发射过程涉及通过碳硼烷簇在供体和受体取代基之间发生强烈的分子内电荷转移。根据这些碳硼烷系统的量子化学计算，电荷转移过程取决于供体和受体基团的相对扭转角，其中桥接碳硼烷簇中两个前沿轨道之间存在重叠。