Assembly of Near‐Infrared Luminescent Lanthanide Host(Host–Guest) Complexes With a Metallacrown Sandwich Motif

Abstract

Oscillators omitted: A self‐assembled inclusion complex between a LnIII[12‐metallacrown‐4]23+ sandwich motif (green and bronze) and a [24‐metallacrown‐8] (purple) is stable in methanol. The YbIII complex has a large quantum yield (0.89 %) and luminescent lifetime (14 μs) in methanol, which are attributed to the exclusion of high‐energy oscillators from within 6.7 Å of the emitting YbIII ion by the metallacrown topology.

Seven‐Coordinate Luminophores: Brilliant Luminescence of Lanthanide Complexes with C3v Geometrical Structures

“…Pecoraro et al reported that one of the important parameters to suppress vibrational relaxation was the distance between the lanthanide ion and the highly oscillated functional groups. [40] We have focused on the carbonyl group, which is the closest group to the lanthanide ion. The IR spectra of carbonyl groups for Eu(tmh)3(tppo) and Eu(hfa)3(tppo)2 are shown in Figure 6a.…”

Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand

“…These entities are of great interest for their aesthetically beautiful structures [2][3][4], unexpected transformations [5][6][7] and potential applications in magnetism [8][9][10], luminescence [11][12][13][14][15], catalysis [16][17][18], etc. Paramagnetic transition metal CCs are of intense interest and have attracted a vast amount of attention since the discovery that some CCs behave as single-molecule magnets (SMMs) [19][20][21].…”

A Family of 12‐Azametallacrown‐4 Structural Motif with Heterometallic MnIII‐Ln‐MnIII‐Ln (Ln=Dy, Er, Yb, Tb, Y) Alternate Arrangement and Single‐Molecule Magnet Behavior

“…The frequency‐dependent ${\chi {^\prime}{^\prime}_{\rm{M}} }$ signals indicate slow relaxation of magnetization, which is typical of SMM‐like behavior. Tail‐like signals in the ${\chi {^\prime}{^\prime}_{\rm{M}} }$ versus T plots have also been seen for other [Mn 2 Ln 2 ] compounds 9. The characteristic maximum of the out‐of‐phase signal could not be observed, and presumably it may be below 1.8 K. We could not go further in the analysis of the slow relaxation process or the determination of the energy barrier and the time constant 32…”

“…Most of these MCs represent the 15‐MC‐5 structural type, mainly with Cu ions as ring metal ions,5c, 6 and only several cases displayed Ni ions in MC rings 7. Interestingly, 15‐MC‐5 complexes usually exhibited guest‐molecule recognition5c, 8 or served as building blocks for one‐dimensional solids 9. For instance, Ln[15‐MC‐5] compartments can recognize carboxylates with phenyl side chains of different lengths 8c.…”

“…The complex Gd[15‐MC CuN(S‐pheHA) ‐5] was linked into one‐dimensional helical chains through carbonyl oxygen atoms and Cu ions from the adjacent metallacrown 10. In addition, a [24‐MC‐8] Zn complex bound the Tb[12‐MC‐4] 2 sandwich through its hydroximate oxygen atom bridging each Zn ion of the [12‐MC‐4] units to form a remarkable host–guest complex 9. In the second group, the MC rings consist of both 3d and 4f ions with the cavities accommodating 4f ions.…”