An Fe(II) SCO complex based on an acylhydrazone ligand with an amino functional group has been prepared. The complex is able to dissociate and regather upon protonation and deprotonation, in both solid state and solution, accompanied by spin state switching, marked change of color, and distinct solubility in water. Moreover, the complex shows distinct magnetic responses toward formaldehyde and protic and nonprotic solvents, as a result of the different affinity of the amino functional site with those chemicals. Communication pubs.acs.org/IC

A new donor–acceptor Stenhouse adduct based on a N,N,N′-trimethylethylenediamine donor has been reported. An unprecedented isomer has been isolated, and rich conversions between three isomers have been achieved upon visible-light irradiation or base/acid stimuli. The drastic color change associated with structural conversion has been utilized to selectively sense volatile primary amines as well as high-charged hard Lewis acids (Sc3+, Ti4+, Cr3+, and Al3+).

Six complexes with the formula [FeL(NCE)2] (E = S, Se, BH3) have been reported. A survey of the magneto-structural relationship has been conducted.

DonorÀ acceptor Stenhouse adducts (DASAs) are a new class of negative photochromic molecules capable of linear-to-cyclic isomerization. We report three new DASAs that are responsive not only to visible-light irradiation, but also to chemical stimuli including acidity and metal ions. The pendant pyridine group in the donor moiety has been found to play an important role in determining the isomerization process and tuning the relative stability of the isomers. Successful isolation of a new double cyclized isomer requires the pyridine nitrogen atom to be in a suitable position where it is able to form a stable six-membered C 4 N 2 ring. The marked change of color associated with the isomerization has been applied for the visual detection of primary amine vapors and Cu 2 + ions.