Tuning white light emission using single-component tetrachroic Dy metallacrowns: the role of chromophoric building blocks.

White light production is of major importance for ambient lighting and technological displays. White light can be obtained by several types of materials and their combinations, but single component emitters remain rare and desirable towards thinner devices that are, therefore, easier to control and that require fewer manufacturing steps. We have designed a series of dysprosium(iii)-based luminescent metallacrowns (MCs) to achieve this goal.

Slow magnetic relaxation in a europium(II) complex.

Single-ion anisotropy is vital for the observation of Single-Molecule Magnet (SMM) properties (i.e., a slow dynamics of the magnetization) in lanthanide-based systems.

Tunable Optical Molecular Thermometers Based on Metallacrowns.

The effect of ligands' energy levels on thermal dependence of lanthanide emission was examined to create new molecular nanothermometers. A series of LnGaLL metallacrowns (shorthand LnL), where Ln = Gd, Tb, or Sm (HL' = salicylhydroxamic acid (Hshi), 5-methylsalicylhydroxamic acid (Hmshi), 5-methoxysalicylhydroxamic acid (Hmoshi), and 3-hydroxy-2-naphthohydroxamic acid (Hnha)) and HL″ = isophthalic acid (Hiph), was synthesized and characterized. Within the series, ligand-centered singlet state (S) energy levels ranged from 23,300 to 27,800 cm, while triplet (T) energy levels ranged from 18,150 to 21,980 cm.

Ethanol(nitrato)[tris-(4-cyano-3-phenyl-1-pyrazol-1-yl)hydroborato]nickel(II).

The synthesis and structure is reported of TpNi(NO)(EtOH) or [Ni(CHBN)(NO)(CHO)], the first half-sandwich complex of a cyano-scorpionate ligand. The pseudo-octa-hedral coordination sphere of the Ni ion is comprised of a tridentate tris-(4-cyano-3-phenyl-pyrazol-yl)borate ligand, a bidentate nitrate ligand and a neutral ethanol ligand. The phenyl substituents on the Tp ligand are relatively parallel to the planes of the ethanol and nitrate ligands.

Visible, Near-Infrared, and Dual-Range Luminescence Spanning the 4f Series Sensitized by a Gallium(III)/Lanthanide(III) Metallacrown Structure.

Lanthanide(III) ions (Ln) in coordination compounds exhibit unique luminescence properties with narrow and characteristic f-f transitions throughout the visible and near-infrared (NIR) ranges. In addition, some Ln such as Pr, Sm, Dy, Ho, Er, and Tm possess an exceptional ability, although less explored, to exhibit dual-range emissions. Such remarkable features allow highly specific use in materials science and biology, for example, for the creation of sophisticated barcode modules or for the next generation of optical imaging applications.

Dy White Light Emission Can Be Finely Controlled by Tuning the First Coordination Sphere of Ga/Dy Metallacrown Complexes.

Single lanthanide(III) ion white light emission is in high demand since it provides the advantage of requiring only one chromophore for the control of the color. Herein, a series of Ga/Dy metallacrowns (MCs) is presented, demonstrating outstanding white light colorimetric properties with CIE chromaticity coordinates of (0.309, 0.

Ultrafast Excited State Dynamics and Fluorescence from Vitamin B and Organometallic [Co]-C≡C-R Cobalamins.

Cobalamins are cobalt-centered cyclic tetrapyrrole ring-based molecules that provide cofactors for exceptional biological processes and possess unique and synthetically tunable photochemistry. Typical cobalamins are characterized by a visible absorption spectrum consisting of peaks labeled α, β, and sh. The physical basis of these peaks as having electronic origin or as a vibronic progression is ambiguous despite much investigation.

[Ga Sm , Ga Tb ] Metallacrowns are Highly Promising Ratiometric Luminescent Molecular Nanothermometers Operating at Physiologically Relevant Temperatures.

Nanothermometry is the study of temperature at the submicron scale with a broad range of potential applications, such as cellular studies or electronics. Molecular luminescent-based nanothermometers offer a non-contact means to record these temperatures with high spatial resolution and thermal sensitivity. A luminescent-based molecular thermometer comprised of visible-emitting Ga /Tb and Ga /Sm metallacrowns (MCs) achieved remarkable relative thermal sensitivity associated with very low temperature uncertainty of S =1.

Exceptional Photochemical Stability of the Co-C Bond of Alkynyl Cobalamins, Potential Antivitamins B and Core Elements of B-Based Biological Vectors.

Alkynylcorrinoids are a class of organometallic B derivatives, recently rediscovered for use as antivitamins B and as core components of B-based biological vectors. They feature exceptional photochemical and thermal stability of their characteristic extra-short Co-C bond. We describe here the synthesis and structure of 3-hydroxypropynylcobalamin (HOPryCbl) and photochemical experiments with HOPryCbl, as well as of the related alkynylcobalamins: phenylethynylcobalamin and difluoro-phenylethynylcobalamin.