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Halogen bonding permeates many areas of chemistry. A wide range of halogen-bond donors including neutral, cationic, monovalent, and hypervalent have been developed and studied. In this work we used density functional theory (DFT), natural bond orbital (NBO) theory, and quantum theory of atoms in molecules (QTAIM) to analyze aryl halogen-bond donors that are neutral, cationic, monovalent and hypervalent and in each series we include the halogens Cl, Br, I, and At. Within this diverse set of halogen-bond donors, we have found trends that relate halogen bond length with the van der Waals radii of the halogen and the non-covalent or partial covalency of the halogen bond. We have also developed a model to calculate ΔGof halogen-bond formation by the linear combination of the % p-orbital character on the halogen and energy of the σ-hole on the halogen-bond donor. 

Abstract Arynes are highly reactive intermediates that may be used strategically in synthesis by trapping with arynophilic reagents. However, ‘arynophilicity’ of such reagents is almost completely anecdotal and predicting which ones will be efficient traps is often challenging. Here, we describe a systematic study to parameterize the arynophilicity of a wide range of reagents known to trap arynes. A relative reactivity scale, based on one-pot competition experiments, is presented by using furan as a reference arynophile and 3-chlorobenzyne as a the aryne. More than 15 arynophiles that react in pericyclic reactions, nucleophilic addition, and σ-bond insertion reactions are parameterized with arynophilicity (A) values, and multiple aryne precursors are applicable. 

Diarylhalonium compounds provide new opportunities as reagents and catalysts in the field of organic synthesis. The three center, four electron (3c–4e) bond is a center piece of their reactivity, but structural variation among the diarylhaloniums, and in comparison with other λ 3 -iodanes, indicates that the model needs refinement for broader applicability. We use a combination of Density Functional Theory (DFT), Natural Bond Orbital (NBO) Theory, and X-ray structure data to correlate bonding and structure for a λ 3 -iodane and a series of diarylchloronium, bromonium, and iodonium salts, and their isoelectronic diarylchalcogen counterparts. This analysis reveals that the s-orbital on the central halogen atom plays a greater role in the 3c–4e bond than previously considered. Finally, we show that our revised bonding model and associated structures account for both kinetic and thermodynamic reactivity for both acyclic phenyl(mesityl)halonium and cyclic dibenzohalolium salts. 

Tellurorhodamine, 9-mesityl-3,6-bis(dimethylamino)telluroxanthylium hexafluorophosphate ( 1 ), photocatalytically oxidizes aromatic and aliphatic silanes and triphenyl phosphine under mild aerobic conditions. Under irradiation with visible light, 1 can react with self-sensitized 1 O 2 to generate the active telluroxide oxidant ( 2 ). Silanes are oxidized to silanols and triphenyl phosphine is oxidized to triphenyl phoshine oxide either using 2 , or 1 with aerobic irradiation. Kinetic experiments coupled with a computational study elucidate possible mechanisms of oxidation for both silane and phosphine substrates. First-order rates were observed in the oxidation of triphenyl phosphine and methyldiphenyl silane, indicating a substitution like mechanism for substrate binding to the oxidized tellurium( iv ). Additionally, these reactions exhibited a rate-dependence on water. Oxidations were typically run in 50 : 50 water/methanol, however, the absence of water decreased the rates of silane oxidation to a greater degree than triphenyl phosphine oxidation. Parallel results were observed in solvent kinetic isotope experiments using D 2 O in the solvent mixture. The rates of oxidation were slowed to a greater degree in silane oxidation by 2 ( k H / k D = 17.30) than for phosphine ( k H / k D = 6.20). Various silanes and triphenyl phosphine were photocatalytically oxidized with 1 (5%) under irradiation with warm white LEDs using atmospheric oxygen as the terminal oxidant. 

Abstract The methoxy‐ and fluoro‐derivatives ofmeta‐nitrophenylacetic acid (mNPA) chromophores undergo photodecarboxylation with comparable quantum yields (Φ) to unsubstitutedmNPA, but uncage at red‐shifted excitation wavelengths. This observation prompted us to investigate DPAdeCageOMe (2‐[bis(pyridin‐2‐ylmethyl)amino]‐2‐(4‐methoxy‐3‐nitrophenyl)acetic acid) and DPAdeCageF (2‐[bis(pyridin‐2‐ylmethyl)amino]‐2‐(4‐fluoro‐3‐nitrophenyl)acetic acid) as Zn²⁺photocages. DPAdeCageOMe has a high Φ and exhibits other photophysical properties comparable to XDPAdeCage ({bis[(2‐pyridyl)methyl]amino}(9‐oxo‐2‐xanthenyl) acetic acid), the best preforming Zn²⁺photocage reported to date. Since the synthesis of DPAdeCageOMe is more straightforward than XDPACage, the new photocage will be a highly competitive tool for biological applications.