Bilayer spin-crossover nanocomposites show robust and controllable actuation cycles upon an electrical stimulus. The anisotropic shape of the particle and the mechanical coupling with the matrix can intensify the work output of the actuators.

Boron and tin complexes have been a versatile and very interesting scaffold for the design of nonlinear optical (NLO) chromophores. In this paper we present a wide range of reports since the 1990s to date, which include second-order (e.g., second harmonic generation) and third-order (e.g., two-photon absorption) NLO properties. After a short introduction on the origin of the NLO response in molecules, the different features associated with the introduction of these inorganic motifs in the organic-based NLO materials are discussed: Their effect on the accepting/donating capabilities of the substituents, on the efficiency of the π-conjugated linkage, and on the topology of the chromophores which can be tuned from the first generation of “push-pull” chromophores to more sophisticated two- or three-dimensional architectures.

A ruthenium–nitrosyl derivative of formula [Ru^II(CzT)(bipy)(NO)](PF₆)₃ [CzT = 4′‐(N‐ethylcarbazol‐3‐yl)‐2,2′:6′,2′′‐terpyridine, bipy = 2,2′‐bipyridine] has been synthesized and fully characterized, and compared with the previously reported [Ru^II(FT)(bipy)(NO)](PF₆)₃ complex [FT = 4′‐(9,9‐dihexyl‐9H‐fluoren‐2‐yl)‐2,2′:6′,2′′‐terpyridine]. Additionally, the X‐ray crystal structure of [Ru^II(CzT)(bipy)(NO₂)](PF₆), the precursor of [Ru^II(CzT)(bipy)(NO)](PF₆)₃, is reported. The presence of a tertiary amine in the carbazole unit leads to redshifted charge‐transfer transitions towards the electron‐withdrawing Ru–NO fragment and hence enhanced two‐photon absorption (TPA) properties. In contrast, the quantum yield of the NO· photorelease process is lower for the carbazole‐containing complex. The issue of optimization of the TPA versus NO·‐release capabilities is addressed.