Halogen Bonding in Solution

2 Chapter 2 Figure 2.1 Association constants between N ‐halosaccharins and 4‐methoxy‐2‐pi... Figure 2.2 Bis(pyridine)halonium ions employed in NMR spectroscopic studies ... Scheme 2.1 Formation of supramolecular capsule 1· 2by fourfold halogen bondin... Figure 2.3 Metal fluoride complexes investigated as halogen bond acceptors.... Scheme 2.2 A tridentate halogen bond donor–acceptor pair. Figure 2.4 Halogen bond donor and acceptor macromolecules. Figure 2.5 Compounds used for the preparation of halogen bond acceptor‐ and ... Figure 2.6 Receptors that incorporate arene‐based halogen bond donors. Figure 2.7 ortho ‐Phenylethynylene derivatives used in spectroscopic studies ... Figure 2.8 Molecular torsion balances used to estimate the strength of halog... Figure 2.9 Representative iodoperfluoroarene‐based multidentate anion recept... Figure 2.10 A sulfonyl‐substituted bis(iodoarene) anion receptor. Figure 2.11 Receptors that employ haloarene groups in combination with other... Figure 2.12 An oligo(phenylene)‐based anion transporter. Figure 2.13 Association constants of a substituted 5‐iodo‐1,2,3‐triazole wit... Scheme 2.3 Self‐complementary halogen bonding species capable of dimerizatio... Figure 2.14 A pH‐switchable self‐complementary halogen bonding motif. Scheme 2.4 Formation of a catenane through pyridine–iodopyridinium halogen b... Figure 2.15 Representative classes of halogenated heterocycles that have bee... Figure 2.16 Anion recognition in aqueous solvent using heteroarene‐derived h...Figure 2.17 Examples of bi‐ and tridentate molecular recognition using iodod...Figure 2.18 Cyclic peptides used to probe halogen bonding interactions of β‐...

3 Chapter 3Figure 3.1 Cartoon representation of the sulfate‐binding protein.Figure 3.2 Resnati and Metrangolo's heteroditopic iodoperfluoroarene recepto...Figure 3.3 Taylor's tripodal receptor capable of Cl −coordination thro...Figure 3.4 Huber's tridentate receptor 3, capable of three‐point XB formatio...Figure 3.5 Most commonly employed XB donors for recognition purposes.Figure 3.6 Beer's macrocyclic haloimidazolium cyclophane receptors.Scheme 3.1 Kubik's tridentate XB cyclo‐pseudopeptide 6.Figure 3.7 Cartoon representation of (a) [2]rotaxane and (b) [2]catenane.Scheme 3.2 (a) Wasserman's statistical synthesis of a [2]catenane. (b) Sauva...Figure 3.8 Chloride anion‐templated assembly of a [2]pseudorotaxane.Scheme 3.3 Discrete chloride anion‐templated assembly of a [2]rotaxane.Scheme 3.4 Chloride anion‐templated assembly of a [2]catenane via amide cond...Scheme 3.5 [2]Pseudorotaxane formation mediated by XB‐anion interactions.Scheme 3.6 Synthesis of the first XB‐anion‐templated [2]rotaxane.Figure 3.9 Beer's XB and HB water‐soluble [2]rotaxanes.Figure 3.10 Beer's series of acyclic XB‐anion receptors with electron‐withdr...Scheme 3.7 Chloride anion‐templated amide condensation clipping reaction syn...Figure 3.11 XB and HB perfluoroaryl‐functionalized [2]rotaxanes.Figure 3.12 Beer's XB [2]rotaxane, capable of binding nitrate in D 2O:[D 6]‐ac...Scheme 3.8 [2]Pseudorotaxanes with a range of XB donors and a pyridine‐based...Figure 3.13 [2]Catenane templated via a single charge‐assisted halogen bond....Figure 3.14 A series of 4‐halopyridinium [2]catenanes as halide receptors....Figure 3.15 A bis‐iodotriazole pyridinium containing [2]catenane.Figure 3.16 Tetradentate XB donor [2]catenane host structure.Figure 3.17 Schematic representation of ambidentate nature of the iodotriazo...Scheme 3.9 The first report of an XB [2]rotaxane synthesis via CuAAC‐AMT rea...Figure 3.18 Truncated structures of monocationic[2]rotaxanes 48–50·PF 6....Figure 3.19 Neutral XB [2]rotaxanes containing regioisomeric macrocycles.Figure 3.20 [2]Rotaxanes with XB donor axle components.Figure 3.21 XB rotaxane with secondary amine functionality in axle and macro...Figure 3.22 Truncated structure showing orthosteric control and conformation...Figure 3.23 Beer's acyclic BINOL‐based receptor 56·PF 6and a [2]rotaxane 57·...Scheme 3.10 A naphthalene‐based [2]catenane synthesized by double clipping X...Figure 3.24 XB [2]rotaxane 60·PF 6capable of anion sensing.Figure 3.25 Ru(II) appended XB rotaxane and acyclic receptor capable of iodi...Figure 3.26 Chiral XB [3]rotaxane capable of dicarboxylate recognition and s...Figure 3.27 Beer's ferrocene appended XB [2]rotaxane capable of electrochemi...Figure 3.28 Truncated structure of 65·2PF 6two‐station [2]rotaxane with anio...Figure 3.29 A mixed XB/HB nitrate‐selective [3]rotaxane shuttle.Figure 3.30 Truncated structure of Beer's pH‐responsive anion shuttle.Figure 3.31 Molina's hydrogen pyrophosphate‐responsive foldamer.Figure 3.32 Berryman's XB‐iodide‐induced triple helicate.Figure 3.33 Beer's XB foldamer, capable of selective iodide recognition in w...Figure 3.34 Representation of the 2 : 1 71:I −complex formed in water....

4 Chapter 4Figure 4.1 Schematic representations of (a) a classical two‐center halogen b...Figure 4.2 The molecular orbital system of the three‐center, four‐electron ...Figure 4.3 The strength of the three‐center halogen bond depends on the natu...Figure 4.4 Schematic presentation of electrophilic halogenation of alkenes. ...Figure 4.5 Structures of the three‐center halogen‐bonded complexes [bis(pyr...Figure 4.6 Energy potentials of halogen motion in a three‐center [D⋯X⋯D] +...Figure 4.7 Calculated NN distances for (a) [(1,2‐bis(pyridin‐2‐ylethynyl)b...Figure 4.8 Crystal structure of [bis(2‐imidazolidinethione)iodine(I)] +...Figure 4.9 Crystal structures of (a) [Se⋯I⋯Se] +complex and (b) two thr...Figure 4.10 The X‐ray structure of an asymmetric three‐center halogen bond c...Figure 4.11 Crystal structures of (a) [bis(pyridine)silver(I)] +OTs −...Figure 4.12 Crystal structures of the halogen bond complexes between (a) N ‐...Figure 4.13 Comparison of the distances between electron donors (NO/N) in ...Figure 4.14 Three‐center halogen bonds undergo proton exchange in protic sol...Figure 4.15 A cyclic bis(pyridine)‐type ligand, designed to study [N⋯X⋯N] +...Figure 4.16 Examples of a three‐center halogen‐bonded (a) capsule and (b) c...Figure 4.17 [Bis(pyridine)iodine(I)] +tetrafluoroborate can be used as ...Figure 4.18 (a) Cyclization reaction of carbonyl groups with alkynes. The r...Figure 4.19 The proposed mechanism of cyclobromination of 4‐penten‐1‐ol ind...Figure 4.20 Reactions of alkenes with halonium ions that are stabilized by ...Figure 4.21 Plausible mechanism for the oxidation reactions of alcohols, as ...Figure 4.22 The mechanism of bromolactonization of unsaturated carboxylic a...Figure 4.23 Structures of (a) (DHQD) 2PHAL and DCDMH [60] and (b) the catalyt...Figure 4.24 Structures of the three‐center halogen‐bonded (a) dimeric and (...Figure 4.25 Crystal structures of three‐center halogen‐bonded (a) dimeric c...Figure 4.26 Crystal structure of the three‐center halogen‐bonded helix. Cou...Figure 4.27 Crystal structures of the three‐center halogen‐bonded [R‐COOI...

5 Chapter 5Figure 5.1 Decomposition of an experimental spectrum of a solution in liquid...Figure 5.2 Gogoi's 2‐chloropyridine–ICl complex.Figure 5.3 Halogen bond complex of molecular iodine and tetramethylthiourea....Figure 5.4 Hydrogen bonding of triethylamine with chloroform (a) versus halo...Figure 5.5 Huber's 2‐haloimidazolium salt and its interaction mode with a tr...Figure 5.6 Interactions of halogen bond donors with solvent molecules. Examp...Figure 5.7 Bowling's system for studying intramolecular halogen bonding.Figure 5.8 β‐Hairpin peptide displaying interstrand halogen bonding.Figure 5.9 Multidentate halogen bonding systems developed by Huber et al. Wh...Figure 5.10 Intramolecular hydrogen bonded–halogen bond in anion binding.Figure 5.11 An example of Diederich's supramolecular capsules held together ...Figure 5.12 Diederich's strong halogen bonding system, where 4‐(2‐iodoethyny...Figure 5.13 Representation of van't Hoff analysis of Diederich's halogen bon...Figure 5.14 Beer's halogen bond acyclic receptor (to the left) that complexe...Figure 5.15 Chemical double‐mutant cycle containing a potential halogen bond...Figure 5.16 Example of a Job plot showing 1 : 1 stoichiometry of binding, wi...Figure 5.17 Taylor's tridentate halogen bond donor, with three separate halo...Figure 5.18 Halogen bond complex of 4‐methylpyridine and Philp's iodotriazol...Figure 5.19 An example of Rissanen's N ‐halosaccharin‐pyridine N ‐oxide haloge...Figure 5.20 Monomers of Jiang's two halogen bonding systems. Top: two repres...Figure 5.21 Berryman's halogen bonding triple helicate from a side‐on perspe...Figure 5.22 Schubert's double bidentate system displaying an orthogonal arra...Figure 5.23 Main NOEs seen in a 1H, 19F HOESY experiment by Ciancaleoni et al...Figure 5.24 Beer's macrocyclic haloimidazolium anion receptor in solution, r...Figure 5.25 Philp's iodotriazole dimer in solution.Figure 5.26 Erdelyi's symmetric [NXN] +system, with 3‐center‐4‐electro...Figure 5.27 TEMPO radical resonance forms.Figure 5.28 Micallef's halogen bond complex of (TMIO) 2‐DITFB.Figure 5.29 Lucarini's organic radical probe displaying halogen bonding to q...