RESUMO
Open hollow dodecahedral cage clusters have long been a coveted target in synthetic chemistry, yet their creation poses immense challenges. Here we report two open hollow dodecahedral lanthanide-aluminum (Ln-Al) heterometallic cage clusters, namely, [Ln210Al140(µ2-OH)210(µ3-OH)540(OAc)180(H2O)156](ClO4)120·(MeCN)x·(H2O)y, (Ln = Dy and x = 27, y = 300 for 1; Ln = Y and x = 28, y = 420 for 2). Remarkably, the 350 metal atoms in 1 and 2 display a Keplerate-type four-shell structure of truncated icosidodecahedron@dodecahedron@dodecahedron@icosidodecahedron. The diameter of the cationic cluster in 1 is approximately 5.0 nm, with an inner cavity diameter of about 2.8 nm and a window diameter of roughly 0.66 nm. The cluster in 1 boasts an accessible inner void volume of up to 15,000 Å3. Notably, these cage clusters maintain stability in water, and the truncated icosidodecahedrons in 1 and 2 are the first of their kind synthesized to date. Given that the open hollow dodecahedral Ln-Al cage cluster has never been reported before, this work represents a member in the family of hollow open dodecahedral cages.
RESUMO
A series of chiral heterometallic Ln-Co clusters, denoted as Co2Ln and Co3Ln2 (Ln = Dy and Er), were synthesized by reacting the chiral chelating ligand (R/S)-2-(1-hydroxyethyl)pyridine (Hmpm), CoAc2·4H2O, and Ln(NO3)3·6H2O. Co2Ln and Co3Ln2 exhibit perfect mirror images in circular dichroism within the 320-700 nm range. Notably, the Co2Er and Co3Er2 clusters display pronounced magnetic circular dichroism (MCD) responses of the hypersensitive f-f transitions 4I15/2-4G11/2 at 375 nm and 4I15/2-2H11/2 at 520 nm of ErIII ions. This study highlights the strong magneto-optical activity associated with hypersensitive f-f transitions in chiral 3d-4f magnetic clusters.
RESUMO
A mixed alkali-metal nonlinear optical (NLO) dihydro-cyanurate crystal Rb3Na(H2C3N3O3)4·3H2O has been synthesized via the hydrothermal method. Its calculated birefringence is about 0.368, which is very large, its ultraviolet (UV) cutoff edge is down to 230 nm, and the powder second harmonic generation (SHG) intensity is about 0.2 × KDP. In addition, a first-principles investigation of the electronic properties on Rb3Na(H2C3N3O3)4·3H2O was carried out. The calculated band gap and SHG coefficient values agree well with the experimental ones. These results suggest that it could be applied as a UV birefringent material.