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1. The Influence of Secondary Interactions on the [N−I−N] + Halogen Bond

   https://doi.org/10.1002/chem.202102575  

   Lindblad, Sofia ; Boróka Németh, Flóra ; Földes, Tamás ; von der Heiden, Daniel ; Vang, Herh G. ; Driscoll, Zakarias L. ; Gonnering, Emily R. ; Pápai, Imre ; Bowling, Nathan ; Erdelyi, Mate ( September 2021 , Chemistry – A European Journal)

   [Bis(pyridine)iodine(I)]⁺complexes offer controlled access to halonium ions under mild conditions. The reactivity of such stabilized halonium ions is primarily determined by their three‐center, four‐electron [N−I−N]⁺halogen bond. We studied the importance of chelation, strain, steric hindrance and electrostatic interaction for the structure and reactivity of halogen bonded halonium ions by acquiring their¹⁵N NMR coordination shifts and measuring their iodenium release rates, and interpreted the data with the support of DFT computations. A bidentate ligand stabilizes the [N−I−N]⁺halogen bond, decreasing the halenium transfer rate. Strain weakens the bond and accordingly increases the release rate. Remote modifications in the backbone do not influence the stability as long as the effect is entirely steric. Incorporating an electron‐rich moiety close by the [N−I−N]⁺motif increases the iodenium release rate. The analysis of the iodine(I) transfer mechanism highlights the impact of secondary interactions, and may provide a handle on the induction of stereoselectivity in electrophilic halogenations.

    

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2. Large N Limit of the O(N) Linear Sigma Model in 3D

   https://doi.org/10.1007/s00220-022-04414-w  

   Shen, Hao ; Zhu, Rongchan ; Zhu, Xiangchan ( June 2022 , Communications in Mathematical Physics)
3. The geometry of N=3$$ \mathcal{N}=3 $$ AdS4 in massive IIA

   https://doi.org/10.1007/JHEP08(2018)133  

   De Luca, G. Bruno ; Monaco, Gabriele Lo ; Macpherson, Niall T. ; Tomasiello, Alessandro ; Varela, Oscar ( August 2018 , Journal of High Energy Physics)
4. Large N limit of the O(N) linear sigma model via stochastic quantization

   https://doi.org/10.1214/21-aop1531  

   Shen, Hao ; Smith, Scott A. ; Zhu, Rongchan ; Zhu, Xiangchan ( January 2022 , The Annals of Probability)
5. Investigation of the Effect of the Trifluoropropynyl Ligand on Pt(N^C^N)X (X = Cl, C2CF3) Complexes

   https://doi.org/10.3390/cryst14080678  

   Zimmerman, John H ; Cahill, Benjamin J ; Thomas, Wilson M ; McCarthy, Jackson S ; McMillen, Colin D ; Wagenknecht, Paul S ( August 2024 , Crystals)

   Fedin, V P (Ed.)

   The tuning of the luminescent properties of PtII complexes for possible use in organic light-emitting diodes (OLEDs) and sensing applications is commonly achieved by altering the electronic properties of the ligands. Our group recently demonstrated that the trifluoropropynyl ligand is strongly electron-withdrawing and possibly useful for blueshifting emission. Herein, we report the synthesis of two complexes of this trifluoropropynyl ligand, namely PtLC2CF3 and PtLFC2CF3 (L = 1,3-di(2-pyridyl)benzene; LF = 4,6-difluoro-1,3-di(2-pyridyl)benzene). The PtLC2CF3 complex crystallized in the monoclinic space group P21/n with Z = 4. The PtLFC2CF3 complex crystalized in the triclinic space group P-1 with Z = 2. Changing the tridentate ligand from L to LF resulted in a change in the packing structure, with the latter showing a metallophilic interaction (Pt-Pt distance = 3.3341(3) Å). The solution photophysics of the trifluoropropynyl complexes is compared with that of the corresponding Cl complexes, PtLCl and PtLFCl. Replacement of the chloro ligand with the trifluoropropynyl ligand blueshifted the monomer emission by less than 5 nm but blueshifted the excimer emission peaks by 15–20 nm. The complexes of the trifluoropropynyl ligand also favor the excimer emission more than the complexes of the chloro ligand. The excimer emission is quenched by dissolved oxygen significantly more than the corresponding monomer emission. The excimer emission and monomer emission are well separated, and the ratio of monomer to excimer emission is strongly dependent on oxygen concentration.

    

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