A Comparative Study on the Thermodynamics of Halogen Bonding of Group 10 Pincer Fluoride Complexes

Abstract

The thermodynamics of halogen bonding of a series of isostructural Group 10 metal pincer fluoride complexes of the type [(3,5‐R2‐tBuPOCOPtBu)MF] (3,5‐R2‐tBuPOCOPtBu=κ3‐C6HR2‐2,6‐(OPtBu2)2 with R=H, tBu, COOMe; M=Ni, Pd, Pt) and iodopentafluorobenzene was investigated. Based on NMR experiments at different temperatures, all complexes 1‐tBu (R=tBu, M=Ni), 2‐H (R=H, M=Pd), 2‐tBu (R=tBu, M=Pd), 2‐COOMe (R=COOMe, M=Pd) and 3‐tBu (R=tBu, M=Pt) form strong halogen bonds with Pd complexes showing significantly stronger binding to iodopentafluorobenzene. Structural and computational analysis of a model adduct of complex 2‐tBu with 1,4‐diiodotetrafluorobenzene as well as of structures of iodopentafluorobenzene in toluene solution shows that formation of a type I contact occurs.

Crystal engineering strategies towards halogen-bonded metal–organic multi-component solids: salts, cocrystals and salt cocrystals

“…This is also the case when halogenides are coordinated to metal ions. Thus the first cocrystal of a metal-organic compound in which the coformers are bonded via I⋯F-Pd halogen bonds has been reported as recently as 2020 by Beweries and coworkers, 94 who have prepared a cocrystal of a fluoropalladium(II) organometallic pincer complex and 14tfib (Fig. 11f).…”

Evaluating Halogen-Bond Strength as a Function of Molecular Structure Using Nuclear Magnetic Resonance Spectroscopy and Computational Analysis

“…A significant portion of the XB research found in the literature are fundamental theoretical/computational studies, − whereas another fraction combines experimental work with complementary computational measurements. ,− Experimental evidence of XB often comes from examining the interaction in the vapor phase, , in the solid phase via X-ray crystallography, ,− or without considering the influence of solvent as in many theoretical investigations. − Experimental studies of XB in solution are significantly fewer in number. Hawthorne and co-workers in 2013 utilized Fourier transform infrared (FT-IR) spectroscopy to characterize changes in vibrational frequencies of heptafluoroiodopropane compounds (XB donors) and pyridine (XB acceptor) as a result of XB interactions .…”

“…FT-IR and UV–vis measurements of XB interactions indicate the presence of XB adducts in solution or show only a semi-quantitative assessment of XB interaction strength . Some solution measurements of XB make use of nuclear magnetic resonance (NMR) spectroscopy to measure the association constants ( K a ) between the two interacting molecules that form an adducta widely accepted technique for assessing the strength of intermolecular interactions, , with very instructive reviews, tutorials, and online resources available (). ,,− ,− Within these studies, however, there is no systematic examination of the structural properties of both the XB donor and the XB acceptor that impact the strength of XB interactions.…”

A C^N Cycloplatinated(II) Fluorido Complex: Photophysical Studies and Csp3‒F Bond Formation

“…The bond length of Pt-F is 2.042 Å, in the typical range of tetracoordinated platinum fluorido complexes. [23][24][25][26][27][28] The platinum adopts a distorted-square-planar coordination geometry with angles ranging from 81.38 to 98.88°; the maximum deviation from the mean plane through PtCNPF is 0.018 Å. The fluorido ligand involves hydrogen bonding interactions with co-crystallized CH2Cl2 solvent 43 (1.950 Å, Figure 2), H 6 of ppy ligand 42 (2.306 Å), and one hydrogen from PPh3 (2.209 Å) of the vicinal molecule.…”

“…16 Our groups have been actively studying cycloplatinated complexes due to their intriguing photophysical and biological properties. [17][18][19][20][21][22] Some Pt(II) [23][24][25][26][27][28] and Pt(IV) [29][30][31][32][33][34][35][36][37] fluoride complexes are known in literature, however, cycloplatinated complexes bearing a Pt-F bond are unprecendented. [38][39][40] To the best of our knowledge, only one report discussed the halide effect on the photophysical properties of Pt(IV) complexes involving all the F, Cl, Br, and I ligands.…”