Toward a Better Determination of Infrared Molar Absorptivities and Dimer Formation Constants in Self‐association Through Hydrogen Bonding: 3‐Ethyl‐2‐methyl‐3‐pentanol in Tetrachloroethylene as an Example

The monomer–dimer self‐association of the dilute 3‐ethyl‐2‐methyl‐3‐pentanol in tetrachloroethylene in the very dilute state was studied by infrared spectroscopy at several temperatures. The solute was deliberately chosen so that higher oligomers were suppressed by the steric hindrance arising from bulky groups on both sides of hydroxyl group. Two linear utility equations were derived to treat, respectively, the integrated absorbance of the monomer band, A _m, and of the dimer band, A _d, as functions of the initially prepared solute concentration, [B ]₀. The respective molar absorptivities were obtained by fitting these equations to the data. Unlike previous methods, the dimerization constant (K ) can be obtained from either A _m or A _d. Any discrepancy between these two values of K serves as a measure of the quality of the data. The values of K at different temperatures were employed to calculate the standard enthalpy and entropy of dimerization by using a van't Hoff plot. The dimer is predominantly in the cyclic form where both hydroxyl protons are hydrogen‐bonded. This is inferred from the following observations: (1) the spectrum displays only two bands between 3300 and 3750 cm⁻¹; (2) the constancy of as a function of [B ]₀ ; and (3) the linearity of both plots [B ]₀/A _m vs. A _m , and [B ]₀/A _d vs. .     

A Consistent Determination of the Dimerization Constants of the Self‐Association of 2,2‐Dimethyl‐3‐ethyl‐3‐pentanol in Carbon Tetrachloride from its Infrared Spectral Data

Two equations of linear type (Eqs. 10 and 17 in the text) have been derived to analyze the IR data to determine the dimerization constant consistently. Equation 10 is to be used to fit the integrated absorbances of the monomer band to obtain the molar monomer absorptivity, ?_m, and dimerization constant, K; Eq. 17 is to be used to fit the integrated absorbances of the dimer bands to obtain the molar dimer absorptivity, ?_d, and dimerization constant, K. Thus the same dimerization constant can be independently determined either from the monomer band or from the dimer band. The discrepancy between the two determined values provides an assessment of the consistency of determination. The monomer‐dimer self‐association of 2,2‐dimethyl‐3‐ethyl‐3‐pentanol in the solvent of carbon tetrachloride was chosen to demonstrate the utility of these two equations.     

Binuclear trans‐Bis(β‐iminoaryloxy)palladium(II) Complexes Doubly Linked with Pentamethylene Spacers: Structure‐Dependent Flapping Motion and Heterochiral Association Behavior of the Clothespin‐Shaped Molecules

The synthesis, structure, and solution‐state behavior of clothespin‐shaped binuclear trans‐bis(β‐iminoaryloxy)palladium(II) complexes doubly linked with pentamethylene spacers are described. Achiral syn and racemic anti isomers of complexes 1 – 3 were prepared by treating Pd(OAc)₂ with the corresponding N,N′‐bis(β‐hydroxyarylmethylene)‐1,5‐pentanediamine and then subjecting the mixture to chromatographic separation. Optically pure (100 % ee) complexes, (+)‐anti‐ 1 , (+)‐anti‐ 2 , and (+)‐anti‐ 3 , were obtained from the racemic mixture by employing a preparative HPLC system with a chiral column. The trans coordination and clothespin‐shaped structures with syn and anti conformations of these complexes have been unequivocally established by X‐ray diffraction studies. ¹H NMR analysis showed that (±)‐anti‐ 1 , (±)‐anti‐ 2 , syn‐ 2 , and (±)‐anti‐ 3 display a flapping motion by consecutive stacking association/dissociation between cofacial coordination planes in [D₈]toluene, whereas syn‐ 1 and syn‐ 3 are static under the same conditions. The activation parameters for the flapping motion (ΔH^≠ and ΔS^≠) were determined from variable‐temperature NMR analyses as 50.4 kJ mol^?1 and 60.1 J mol^?1 K^?1 for (±)‐anti‐ 1 , 31.0 kJ mol^?1 and ?22.7 J mol^?1 K^?1 for (±)‐anti‐ 2 , 29.6 kJ mol^?1 and ?57.7 J mol^?1 K^?1 for syn‐ 2 , and 35.0 kJ mol^?1 and 0.5 J mol^?1 K^?1 for (±)‐anti‐ 3 , respectively. The molecular structure and kinetic parameters demonstrate that all of the anti complexes flap with a twisting motion in [D₈]toluene, although (±)‐anti‐ 1 bearing dilated Z‐shaped blades moves more dynamically than I‐shaped (±)‐anti‐ 2 or the smaller (±)‐anti‐ 3 . Highly symmetrical syn‐ 2 displays a much more static flapping motion, that is, in a see‐saw‐like manner. In CDCl₃, (±)‐anti‐ 1 exhibits an extraordinary upfield shift of the ¹H NMR signals with increasing concentration, whereas solutions of (+)‐anti‐ 1 and the other syn/anti analogues 2 and 3 exhibit negligible or slight changes in the chemical shifts under the same conditions, which indicates that anti‐ 1 undergoes a specific heterochiral association in the solution state. Equilibrium constants for the dimerizations of (±)‐ and (+)‐anti‐ 1 in CDCl₃ at 293 K were estimated by curve‐fitting analysis of the ¹H NMR chemical shift dependences on concentration as 26 M ^?1 [K_D(racemic)] and 3.2 M ^?1 [K_D(homo)], respectively. The heterochiral association constant [K_D(hetero)] was estimated as 98 M ^?1, based on the relationship K_D(racemic)=1/2 K_D(homo)+1/4 K_D(hetero). An inward stacking motif of interpenetrative dimer association is postulated as the mechanistic rationale for this rare case of heterochiral association.     

Quantum‐chemical,IR, NMR,and X‐ray diffraction studies on 2‐(4‐chlorophenyl)‐1‐methyl‐ 1H‐benzo[d]imidazole

The title molecule, 2‐(4‐chlorophenyl)‐1‐methyl‐1H‐benzo[d]imidazole (C₁₄H₁₁ClN₂), was prepared and characterized by ¹H NMR, ¹³C NMR, IR, and single‐crystal X‐ray diffraction. The molecular geometry, vibrational frequencies, and gauge including atomic orbital (GIAO) ¹H and ¹³C NMR chemical shift values of the title compound in the ground state have been calculated by using the Hartree‐Fock (HF) and density functional theory (DFT/B3LYP) method with 6‐31G(d) basis sets, and compared with the experimental data. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies and GIAO ¹H and ¹³C NMR chemical shifts show good agreement with experimental values. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6‐31G(d) basis set by applying the Onsager and the polarizable continuum model (PCM). Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, and nonlinear optical (NLO) properties of the title compound were investigated by theoretical calculations. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Deuterium‐induced isotope effects on the 13C chemical shifts of α‐d‐glucose pentaacetate

1,2,3,4,6‐Penta‐O‐acetyl‐α‐d ‐glucopyranose and the corresponding [1‐²H], [2‐²H], [3‐²H], [4‐²H], [5‐²H], and [6,6‐²H₂]‐labeled compounds were prepared for measuring deuterium/hydrogen‐induced effects on ¹³C chemical shift ⁿΔ (DHIECS) values. A conformational analysis of the nondeuterated compound was achieved using density functional theory (DFT) molecular models that allowed calculation of several structural properties as well as Boltzmann‐averaged ¹³C NMR chemical shifts by using the gauge‐including atomic orbital method. It was found that the DFT‐calculated C–H bond lengths correlate with ¹Δ DHIECS. Copyright © 2013 John Wiley & Sons, Ltd.     

Rapid analysis of interaction between six drugs and β2‐adrenergic receptor by injection amount‐dependent method

Drug–protein interaction analysis has become a considerable topic in life science which includes clarifying protein functions, explaining drug action mechanisms and uncovering novel drug candidates. This work was to determine the association constants (K _A ) of six drugs to β ₂‐adrenergic receptor by injection amount‐dependent method using stationary phase containing the immobilized receptor. The values of K _A were calculated to be (25.85 ± 0.035) × 10⁴ m ⁻¹ for clorprenaline, (42.51 ± 0.054) × 10⁴ m ⁻¹ for clenbuterol, (6.67 ± 0.008) × 10⁴ m ⁻¹ for terbutaline, (33.99 ± 0.025) × 10⁴ m ⁻¹ for tulobuterol, (7.59 ± 0.011) × 10⁴ m ⁻¹ for salbutamol and (78.52 ± 0.087) × 10⁴ m ⁻¹ for bambuterol. This rank order agreed well with the data determined by zonal elution, frontal analysis and nonlinear chromatography, even using different batches of β ₂‐AR column. A good correlation was found between the association constants by the current method and radio‐ligand binding assay. Our data indicates that the injection amount‐dependent method is a powerful alternative for rapid analysis of ligand–receptor interactions.     

Facile Synthesis and Properties of 2‐λ5‐Phosphaquinolines and 2‐λ5‐Phosphaquinolin‐2‐ones

Treatment of 2‐ethynylanilines with P(OPh)₃ gives either 2,2‐diphenoxy‐2‐λ⁵‐phosphaquinolines or 2‐phenoxy‐2‐λ⁵‐phosphaquinolin‐2‐ones under transition‐metal‐free conditions. This reaction offers access to an underexplored heterocycle, which opens up the study of the fundamental nature of the N?P^V double bond and its potential for delocalization within a cyclic π‐electron system. This heterocycle can serve as a carbostyril mimic, with application as a bioisostere for pharmaceuticals based on the 2‐quinolinone scaffold. It also holds promise as a new fluorophore, since initial screening reveals quantum yields upwards of 40 %, Stokes shifts of 50–150 nm, and emission wavelengths of 380–540 nm. The phosphaquinolin‐2‐ones possess one of the strongest solution‐state dimerization constants for a D–A system (130 M ^?1) owing to the close proximity of a strong acceptor (P?O) and a strong donor (phosphonamidate N? H), which suggests that they might hold promise as new hydrogen‐bonding hosts for optoelectronic sensing.     

Walking Metals in d8⋅⋅⋅d8 Hetero‐bimetallic Complexes: An Original Dynamic Phenomenon

In the course of our investigations on polymetallic complexes derived from 1,3‐bis(thiophosphinoyl)indene (Ind(Ph₂P?S)₂), we observed original fluxional behavior and report herein a joint experimental/computational study of this dynamic process. Starting from the indenylidene chloropalladate species [Pd{Ind(Ph₂P?S)₂}Cl]^? ( 1 ), the new Pd^II???Rh^I hetero‐bimetallic pincer complex [PdCl{Ind(Ph₂P?S)₂}Rh(nbd)] ( 2 ; nbd=2,5‐norbornadiene) was prepared. X‐ray crystallography and DFT calculations substantiate the presence of a d⁸???d⁸ interaction. According to multinuclear variable‐temperature NMR spectroscopic experiments, the pendant {Rh(nbd)} fragment of 2 readily shifts in solution at room temperature between the two edges of the SCS tridentate ligand. To assess the role of the pincer‐based polymetallic structure on this fluxional behavior, the related monometallic Rh complex [Rh{IndH(Ph₂P?S)₂}(nbd)] ( 3 ) was prepared. No evidence for a metal shift was observed in that case, even at high temperature, thus indicating that inplane pincer coordination to the Pd center plays a crucial role. The previously described Pd^II???Ir^I bimetallic complex 4 exhibited fluxional behavior in solution, but with a significantly higher activation barrier than 2 . This finding demonstrates the generality of this metal‐shift process and the strong influence of the involved metal centers on the associated activation barrier. DFT calculations were performed to shed light onto the mechanism of such metal‐shift processes and to identify the factors that influence the associated activation barriers. Significantly different pathways were found for bimetallic complexes 2 and 4 on one hand and the monometallic complex 3 on the other hand. The corresponding activation barriers predicted computationally are in very good agreement with the experimental observations.     

Carbon‐13 NMR and PM3 Study on the Substituent Effect of 1‐Aryl‐3,3‐Difluoro‐2‐Halocyclopropenes

The substituent‐induced chemical shifts (SCS) of C2 and C3 on the ¹³C NMR spectra of 1‐aryl‐3,3‐difluoro‐2‐halocyclopropenes were studied. The correlation between SCS and Hammett constants shows that the tendency of effect by the substituents on the phenyl ring is BrC2(ρ = 4.66) > ClC2(ρ = 4.50) and ClC3(ρ = ?1.63) > BrC3(ρ = ?1.41). The DSP treatment further confirms the SCS of C2 and C3 are the main contribution of the resonance effect and field effect, respectively. Those results of the incremental shifts reveals that the gem‐difluorocyclopropenyl bearing the phenyl group possesses a triple bond character, which is also observed in IR spectra with high n?_C=C (1768–1945 cm^?1).     

Metal‐Mediated Self‐Assembly of a β‐Sandwich Protein

The β‐sandwich cupredoxin Plastocyanin (Pc) was found to self‐assemble in the presence of Zn²⁺, a known mediator of protein–protein interfaces. Diffraction‐quality crystals of Pc grew from solutions containing zinc acetate as the sole precipitant. Di‐ and trinuclear zinc sites contribute to the crystal contacts in this structure. A different crystal form, also involving numerous zinc bridging ions, was obtained in the presence of poly(ethylene glycol) 8 000. Comparison of the two crystal forms reveals the effect of macromolecular crowding on self‐assembly. Solution‐state structural characterisation of the Zn²⁺‐mediated Pc oligomers was performed by using a combination of chemical shift perturbation mapping and small‐angle X‐ray scattering. The data indicate the formation of dimers in solution. The implications for metal‐mediated assembly and crystallisation are discussed.     

The structure‐dependent self‐association of five phenolic acids in aqueous solution

Weak self‐interaction plays an important role in interpreting the biomechanisms and modes of drug action. The structure‐dependent self‐association of five phenolic acids with various bioactivities, including danshensu (DSS), caffeic acid (CA), rosmarinic acid (RA), lithospermic acid (LA), and salvianolic acid B (SA), was investigated by ¹H NMR. These phenolic acids have similar condensed structures, with a CA moiety and varying numbers of DSS moieties. The strengths of the self‐association constants are in the order DSS < CA < RA < LA < SA, which corresponds to the increasing molecular size of these phenolic acids and roughly corresponds to the increasing number of DSS moieties. The binding site for the self‐aggregation of these phenolic acids has been identified to be on the CA moiety, rather than on the DSS moiety, as a result of CA's stronger aromatic π–π interactions, which cause larger chemical shift variations. The thermodynamic parameters for the self‐association of these phenolic acids show that the self‐association is spontaneous and enthalpically favorable at room temperature in all cases. It was inferred that π–π interactions and intermolecular hydrogen bonding stabilize the stacking structures of the phenolic acids. Knowledge of self‐association processes will enable us to quantitatively assess the possible effects of self‐aggregation on the interaction between drug and protein. Copyright © 2014 John Wiley & Sons, Ltd.     

N7‐ and N9‐substituted purine derivatives: a 15N NMR study

The ¹⁵N NMR chemical shifts of N⁷‐ and N⁹‐substituted purine derivatives were investigated systematically at the natural abundance level of the ¹⁵N isotope. The NMR chemical shifts were determined and assigned using GSQMBC, GHMBC, GHMQC and GHSQC experiments in solution. ¹⁵N cross‐polarization magic angle spinning data were recorded for selected compounds in order to study the principal values of the ¹⁵N chemical shifts. Geometric parameters obtained by using RHF/6–31G** and single‐crystal x‐ray structural analysis were used to calculate the chemical‐shielding constants (GIAO and IGLO) which were then used to assign the nitrogen resonances observed in the solid‐state NMR spectra and to determine the orientation of the principal components of the shift tensors. Copyright © 2002 John Wiley & Sons, Ltd.     

A novel azocompound, 2‐(4‐phenylazoaniline)‐4‐phenylphenol: Spectroscopic and quantum‐chemical approach

A novel azocompound with two nonequivalents azo groups, 2‐(4‐phenylazoaniline)‐4‐phenylphenol, was synthesized and characterized by spectroscopic and computational analysis. An intramolecular hydrogen bonding (HB), ? O₁? H₁ ··· N₁? , involving the ? N₁?N₂? group and the proton in a neighbor hydroxyl moiety, was identified. It was found responsible for a characteristic π‐conjugated H₁? O₁? C₁₈?C₁₃? N₂?N₁? six‐membered cyclic fragment. It is worth noting that this azo group is involved in an azo‐hydrazo equilibrium, being the azo form the most stable one. This resonance‐assisted HB was characterized using the OH‐related infrared bands and the corresponding signals in ¹H NMR. In addition, conformational studies and geometrical and electronic parameter calculations were performed using the density functional theory, at B3LYP/6‐311++G** level. Bond and ring critical points were identified using the atoms in molecules theory, which allowed confirming the intramolecular HB. The second azo‐group cannot be involved in HB, but it also presents two stereoisomerics forms corresponding to cis (Z) and trans (E) configurations, with the later being the one with the lowest energy. © 2013 Wiley Periodicals, Inc.     

Synthesis and Self‐Association of Double‐Helical AADD Arrays

The design and syntheses of four self‐complementary oligomers that contain an underlying AADD hydrogen bond sequence are presented, and their self‐association was examined in the solution and solid state. The molecular recognition between the two strands is highly sensitive to substitutions of their component heterocycles. Substitution with electron‐donating and ‐withdrawing groups and the influence of preorganization has a large effect on the overall stabilities of the complexes studied. In particular, a wide range (>10⁵ M ^?1) of stabilities with respect to substitutions at various positions in the AADD oligomers was demonstrated. In the most extreme case, the dimerization constant measured (K_dimer≥4.5×10⁷ M ^?1) is comparable to the most stable homodimers of neutral AADD arrays reported to date.     

1‐Silacyclopent‐2‐enes and 1‐silacyclohex‐2‐enes bearing functionally substituted silyl groups in 2‐positions. Novel electron‐deficient Si?H?B bridges

The reactions of alkyn‐1‐yl(vinyl)silanes R₂Si[C?C‐Si(H)Me₂]CH?CH₂ [R = Me (1a), Ph (1b)], Me₂Si[C?C‐Si(Br)Me₂]CH?CH₂ (2a), and of alkyn‐1‐yl(allyl)silanes R₂Si[C?C‐Si(H)Me₂]CH₂CH?CH₂ (R = Me (3a), R = Ph (3b)] with 9‐borabicyclo[3.3.1]nonane in a 1:1 ratio afford in high yield the 1‐silacyclopent‐2‐ene derivatives 4a, b and 5a, and the 1‐silacyclohex‐2‐ene derivatives 6a, b, respectively, all of which bear a functionally substituted silyl group in 2‐position and the boryl group in 3‐position. This is the result of selective intermolecular 1,2‐hydroboration of the vinyl or allyl group, followed by intramolecular 1,1‐organoboration of the alkynyl group. In the cases of 4a, b, potential electron‐deficient Si? H? B bridges are absent or extremely weak, whereas in 6a,b the existence of Si? H? B bridges is evident from the NMR spectroscopic data (¹H, ¹¹B, ¹³C and ²⁹Si NMR). The molecular structure of 4b was determined by X‐ray analysis. Copyright © 2005 John Wiley & Sons, Ltd.     

A Metal‐free Approach to 3‐Aryl‐3‐hydroxy‐2‐oxindoles by Treatment of 3‐Acyloxy‐2‐oxindoles with Diaryliodonium Salts

A mild, metal‐free approach has been realized for the facile construction of highly valuable 3‐(hetero)aryl‐3‐hydroxy‐2‐oxindoles. Direct arylations of 3‐acyloxy‐2‐oxindoles with diaryliodonium salts as arylation reagents are implemented in the presence of K₂CO₃ at room temperature without using an organometallic promoter to deliver an array of 3‐(hetero)aryl‐3‐hydroxy‐2‐oxindoles in good yields.     

The Effects of Microenvironment Polarity and Dendritic Branching of Aliphatic Hydrocarbon Dendrons on the Self‐Assembly of 2‐Ureido‐4‐pyrimidinones

Two series of aliphatic hydrocarbon‐based G1–G3 dendritic 2‐ureido‐4‐pyrimidinones (UPy) ( S‐Gn )₂ and ( L‐Gn )₂, differing from one another by the distance between the branching juncture to the urea end, were prepared and characterized. These hydrocarbon dendrons were also appended to a p‐aminonitrobenzene solvatochromic chromophore in order to probe their microenvironment polarity. While positive solvatochromism was observed which indicated the chromophore was solvent accessible, there was no significant difference between the microenvironment polarities on going from the G1 to the G3 dendrons. The self‐assembling behavior and tautomeric preference of the dendritic UPy derviatives were examined by ¹H NMR spectroscopy. The dimerization constants (K_dim*) of the DDAA tautomers were unchanged at 10⁷ M ^?1 in CDCl₃ at both 25 and 50 °C, which were comparable to those of UPy compounds bearing other nonpolar substitutents. Furthermore, the lower limits on the K′_dim* of the DADA tautomeric forms of the ( S‐Gn )₂ and ( L‐Gn )₂ series were determined to be 10⁶ and 10⁵ M ^?1 in CDCl₃, respectively. It was found that a closer proximity of the dendron branching juncture to the UPy unit could lead to a destabilization effect on the dimeric states. Hence, the ( L‐Gn )₂ dimers are more stable than those of ( S‐Gn )₂ in the DDAA form, but the latter are more stable than the former in the tautomeric DADA state. This study showed that both the highly nonpolar microenvironment and the proximity of the dendritic branching juncture to the UPy motif could alter the strength and profile of the hydrogen bond‐mediated self‐assembling process.     

The Substituent Effect of 1‐Arylazonaphthen‐2‐ols on Azo‐hydrazone Tautomerization According to NMR Analysis

The substituent effect on azo‐hydrazone tautomerization of 1‐arylazonaphthen‐ols is studied by means of NMR analysis. Among the ¹³C chemical shifts, the C(2) of this series compound is the most sensitive to the variation in the nature of substituent on the phenyl ring. Therefore, the variation in the chemical shifts of C(2) is used to probe the substituent effect by using the substituent chemical shifts and free energy vs. Hammett’s constant (χρ⁺). Both methods give a negative correlation slope, indicating the electron‐with‐ drawing groups favor the hydrazone tautomer form. The effect on the chemical shifts of C(2) of compound 8 in ten solvents can be classified as the solvent with a proton‐donor, proton‐acceptor and arenes system. The substituent with electron‐donating character is more sensitive to the nature of solvent and it favors the hydrazone form. Free energy obtained from the dynamic NMR technique indicates the tautomerization favors the hydrazone‐form for the substituent with electron‐withdrawing character.     

An experimental and computational approach to pH‐dependent self‐aggregation of poly(2‐isopropyl‐2‐oxazoline)

Besides temperature, self‐aggregation of poly(2‐isopropyl‐2‐oxazoline) (PIPOX) can also be triggered via pH in aqueous solution (25 °C, pH > 5). Lowest energy structures and interaction energies of PIPOX with H₃O⁺, OH^?, and H₂O were calculated by DFT methods showed that, in addition to their ability to protonate PIPOX, H₃O⁺ ions had strong interaction with both water and PIPOX in acidic conditions. H₃O⁺ ions acted as compatibilizer between PIPOX and water and increased the solubility of PIPOX. OH^? ions were found to have stronger interaction with water compared to PIPOX resulting in desorption of water molecules from PIPOX phase and decreased solubility, leading to enhanced hydrophobic interactions among isopropyl groups of PIPOX and formation of aggregates at high pH. Results concerning the effect of end‐groups on aggregate size were in good agreement with statistical mechanics calculations. Moreover, the effect of polymer concentration on the aggregate size was examined. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 210–221     

Multiple Pentafluorophenylation of 2,2,3,3,5,6,6‐Heptafluoro‐3,6‐dihydro‐2H‐1,4‐oxazine with an Organosilicon Reagent: NMR and DFT Structural Analysis of Oligo(perfluoroaryl) Compounds

The reagent Me₃Si(C₆F₅) was used for the preparation of a series of perfluorinated, pentafluorophenyl‐substituted 3,6‐dihydro‐2H‐1,4‐oxazines ( 2 – 8 ), which, otherwise, would be very difficult to synthesize. Multiple pentafluorophenylation occurred not only on the heterocyclic ring of the starting compound 1 (Scheme), but also in para position of the introduced C₆F₅ substituent(s) leading to compounds with one to three nonafluorobiphenyl (C₁₂F₉) substituents. While the tris(pentafluorophenyl)‐substituted compound 3 could be isolated as the sole product by stoichiometric control of the reagent, the higher‐substituted compounds 5 – 8 could only be obtained as mixtures. The structures of the oligo(perfluoroaryl) compounds were confirmed by ¹⁹F‐ and ¹³C‐NMR, MS, and/or X‐ray crystallography. DFT simulations of the ¹⁹F‐ and ¹³C‐NMR chemical shifts were performed at the B3LYP‐GIAO/6‐31++G(d,p) level for geometries optimized by the B3LYP/6‐31G(d) level, a technique that proved to be very useful to accomplish full NMR assignment of these complex products.