Strain‐Induced Structural Rearrangement Towards a White‐Light‐Emitting Adamantane‐Type Cluster Dimer

Group 14/16 adamantane-type hybrid clusters of the type [(RT)₄E₆] (T=group 14 element, E=group 16 element, R=organic group) have been reported to emit white-light when irradiated in an amorphous state with a continuous-wave (CW) infrared laser diode. This effect is enhanced if the cluster core is varied from a binary to a more complex composition. To further explore this phenomenon, we synthesized clusters with a multinary R/R'-T/T'-E/E' composition, including isolobal replacement of E with CH₂, in [(2-NpSi){CH₂Sn(S)Ph}₃] (1, Np=naphthyl). When expanding one of the CH₂ moieties to a C₂H₄ group, thus generating a R/R'-T/T'-E/E'/E'' cluster composition, we unexpectedly observed a dimerization of the initially formed, yet non-isolable adamantane-like cluster [(2-NpSi){CH₂Sn(S)Ph}₂{C₂H₄Sn(S)Ph}] (2) to [(2-NpSi){CH₂Sn(S)Ph}₂{C₂H₄Sn(S)Ph}]₂ (3), exhibiting a heretofore unprecedented cluster architecture. Both monomeric 1 and dimeric 3, show white-light emission as thin films. The nonlinear optical response of the compounds was also modelled with DFT methods.