Comparison of N···I and N···O Halogen Bonds in Organoiodine Cocrystals of Heterocyclic Aromatic Diazine Mono-N-oxides.

A series of cocrystals of halogen bond donors 1,4-diiodotetrafluorobenzene (p-F4DIB) and tetraiodoethylene (TIE) with five aromatic heterocyclic diazine mono-N-oxides based on pyrazine, tetramethylpyrazine, quinoxaline, phenazine, and pyrimidine as halogen bonding acceptors were studied. Structural analysis of the mono-N-oxides allows comparison of the competitive occurrence of N···I vs O···I interactions and the relative strength and directionality of these two types of interactions. Of the aromatic heterocyclic diazine mono-N-oxide organoiodine cocrystals examined, six exhibited 1:1 stoichiometry, forming chains that utilized both N···I and O···I interactions. Two cocrystals presented 1:1 stoichiometry with exclusive O···I interactions. Two cocrystals displayed a 2:1 stoichiometry-one characterized solely by O···I interactions and the other solely by N···I interactions. We have also compared these interactions to those present in the corresponding diazines, some of which we report here and some which have been previously reported. In addition, a computational analysis using density functional theory (M062X/def2-SVPD) was performed on these two systems and has been compared to the experimental results. The calculated complex formation energies were, on average, 4.7 kJ/mol lower for the I···O halogen bonding interaction as compared to the corresponding N···I interaction. The average I···O interaction distances were calculated to be 0.15 Å shorter than the corresponding I···N interactions.

Halogen, chalcogen, and hydrogen bonding in organoiodine cocrystals of heterocyclic thiones: imidazolidine-2-thione, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole.

Through the combination of heterocyclic thiones with variation in the identity of the heterocyclic elements, namely, imidazolidine-2-thione, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole with the common halogen-bond donors 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene, 1,3,5-trifluorotriiodobenzene, and tetraiodoethylene, a series of 18 new crystalline structures were characterized. In most cases, N-H...S hydrogen bonding was observed, with these interactions in imidazole-containing structures typically resulting in two-dimensional motifs (i.e. ribbons). Lacking the second N-H group, the thiazole and oxazole hydrogen bonding resulted in only dimeric pairs. C-I...S and C-I...I halogen bonding, as well as C=S...I chalcogen bonding, served to consolidate the packing by linking the hydrogen-bonding ribbons or dimeric pairs.

The reaction of thiourea and 1,3-dimethylthiourea towards organoiodines: oxidative bond formation and halogen bonding.

By varying the halogen-bond-donor molecule, 11 new halogen-bonding cocrystals involving thiourea or 1,3-dimethylthiourea were obtained, namely, 1,3-dimethylthiourea-1,2-diiodo-3,4,5,6-tetrafluorobenzene (1/1), C6F4I2·C3H8N2S, 1, thiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene (1/1), C6F4I2·CH4N2S, 2, 1,3-dimethylthiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene (1/1), C6F4I2·C3H8N2S, 3, 1,3-dimethylthiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene-methanol (1/1/1), C6F4I2·C3H8N2S·CH4O, 4, 1,3-dimethylthiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene-ethanol (1/1/1), C6F4I2·C3H8N2S·C2H6O, 5, 1,3-dimethylthiourea-1,4-diiodo-2,3,5,6-tetrafluorobenzene (1/1), C6F4I2·C3H8N2S, 6, 1,3-dimethylthiourea-1,3,5-trifluoro-2,4,6-triiodobenzene (1/1), C6F3I3·C3H8N2S, 7, 1,3-dimethylthiourea-1,1,2,2-tetraiodoethene (1/1), C6H16N4S2·C2I4, 8, [(dimethylamino)methylidene](1,2,2-triiodoethenyl)sulfonium iodide-1,1,2,2-tetraiodoethene-acetone (1/1/1), C5H8I3N2S+·I-·C3H6O·C2I4, 9, 2-amino-4-methyl-1,3-thiazol-3-ium iodide-1,1,2,2-tetraiodoethene (2/3), 2C4H7N2S+·2I-·3C2I4, 10, and 4,4-dimethyl-4H-1,3,5-thiadiazine-3,5-diium diiodide-1,1,2,2-tetraiodoethene (2/3), 2C5H12N4S2+·4I-·3C2I4, 11. When utilizing the common halogen-bond-donor molecules 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene, as well as 1,3,5-trifluoro-2,4,6-triiodobenzene, bifurcated I...S...I interactions were observed, resulting in the formation of isolated rings, chains, and sheets. Tetraiodoethylene (TIE) provided I...S...I cocrystals as well, but further yielded a sulfonium-containing product through the reaction of the S atom with TIE. This particular sulfonium motif is the first of its kind to be structurally characterized, and is stabilized in the solid state through a three-dimensional I...I halogen-bonding network. Thiourea reacted with acetone in the presence of TIE to provide two novel heterocyclic products, again stabilized in the solid state through I...I halogen bonding.

Halogen Bonding in Dithiane/Iodofluorobenzene Mixtures: A New Class of Hydrophobic Deep Eutectic Solvents.

While research into deep eutectic solvents (DESs) has expanded over the previous two decades, the focus has remained on the utilization of hydrogen bond donors in these systems. Additionally, the majority of the known DESs rely on at least one ionic component. Through the combination of 1,3-dithiane and 1,2-diiodo-3,4,5,6-tetrafluorobenzene (1,2-F4 DIB), we report the first known DES based on halogen bonding. This mixture remains a liquid, with a eutectic melting temperature of 13.7 °C over a range of 1,3-dithiane mole fraction (0.35 to 0.75). Additionally, cocrystals of 1,3- and 1,4-dithiane with 1,2-, 1,3-, and 1,4-F4 DIB, as well as 1,3,5-trifluoro-2,4,6-triiodobenzene were studied via single-crystal X-ray diffraction. These data reveal a wide range of halogen bonding strengths (0.85

Polymorphism, Halogen Bonding, and Chalcogen Bonding in the Diiodine Adducts of 1,3- and 1,4-Dithiane.

Through variations in reaction solvent and stoichiometry, a series of S-diiodine adducts of 1,3- and 1,4-dithiane were isolated by direct reaction of the dithianes with molecular diiodine in solution. In the case of 1,3-dithiane, variations in reaction solvent yielded both the equatorial and the axial isomers of S-diiodo-1,3-dithiane, and their solution thermodynamics were further studied via DFT. Additionally, S,S'-bis(diiodo)-1,3-dithiane was also isolated. The 1:1 cocrystal, (1,4-dithiane)·(I2) was further isolated, as well as a new polymorph of S,S'-bis(diiodo)-1,4-dithiane. Each structure showed significant S···I halogen and chalcogen bonding interactions. Further, the product of the diiodine-promoted oxidative addition of acetone to 1,4-dithiane, as well as two new cocrystals of 1,4-dithiane-1,4-dioxide involving hydronium, bromide, and tribromide ions, was isolated.

Halogen and Chalcogen Bonding Between the Triphenylphosphine Chalcogenides (Ph3 P=E; E=O, S, Se) and Iodofluorobenzenes.

A series of cocrystals of Ph3 P=E (E=O, S, Se) with organoiodines were studied to understand the roles of noncovalent interactions including chalcogen (ChB) and halogen (XB) bonding in their formation. The structure of the cocrystal of Ph3 P=S and 1,2-diiodotetrafluorobezene was determined, which demonstrates a similar chalcogen⋅⋅⋅iodine XB pattern to the previously reported isomorphic Ph3 P=Se structure. The cocrystalline structures resulting from the combination of 1,3-diiodotetrafluorobenzene (1,3-F4 DIB), as well as iodopentafluorobenzene, with all three triphenylphosphine chalcogenides, were also determined. The (Ph3 P=Se) ⋅ (1,3-F4 DIB) cocrystal presents a rare example of a selenium⋅⋅⋅organoiodine ChB. The observed ChB and XB interactions have normalized distance parameters (RXB ) ranging from 0.80 to 0.98. The strength of the XB and ChB interactions were analyzed using natural bond orbital (NBO) theory, with calculated energies falling between 3.14 kcal/mol and 12.81 kcal/mol.

Crystal Engineering Using Polyiodide Halogen and Chalcogen Bonding to Isolate the Phenothiazinium Radical Cation and Its Rare Dimer, 10-(3-Phenothiazinylidene)phenothiazinium.

Utilizing facile one-electron oxidation of 10H-phenothiazine by molecular diiodine, the solid-state structure of the 10H-phenothiazinium radical cation was obtained in three cation:iodide ratios, as well as its THF and acetone solvates. Oxidation of 10H-phenothiazine with molecular diiodine in DMSO or DMF provided the structure of the radical coupling product 10-(3-phenothiazinyldene)phenothiazinium, which has not been crystallographically characterized to date. The radical cations were balanced by a mixture (I7 )- , (I5 )- , (I3 )- , and I- anions, where a variety of chalcogen, halogen, and hydrogen bonding interactions stabilize the structures to reveal these interesting cationic species.

Halogen Bonding of Organoiodines and Triiodide Anions in (NMe3 Ph)+ Salts.

To study the role of the triiodide (I3 )- anion in establishing various halogen bonding patterns, the trimethylphenylammonium iodide (NMe3 PhI) salt was reacted with diiodine (I2 ) in the presence of a series of organoiodines, tetraiodoethylene (TIE), 1,2-diiodo-3,4,5,6-tetrafluorobenzene (o-F4 DIB), 1,4-diiodo-2,3,5,6-tetrafluorobenzene (p-F4 DIB), and 1,3,5-trifluoro-2,4,6-triiodobenzene (1,3,5-F3 I3 B) to form cocrystals of the organoiodines with the trimethylphenylammonium triiodide (NMe3 PhI3 ) salt. Single-crystal X-ray crystallography revealed the (I3 )- anion served as a halogen bond acceptor for the organoiodine donors, forming a variety of 1-D, 2-D, and 3-D packing arrangements through I⋅⋅⋅I halogen bonding. Significant asymmetry was observed within the (I3 )- anion. The melting points of the cocrystalline materials, as determined by simultaneous DSC/TGA, ranged from 43 °C to 119 °C and showed a strong dependence on the identity of the organoiodine incorporated into the crystal lattice.

Detecting and correlating bacterial populations to visual color change of polydiacetylene-coated filters.

Membrane filters were coated with 10,12-pentacosadiynoic acid (PCDA) then polymerized on the filter for rapid bacterial detection and quantification. The polymerized PCDA (pPDCA)-coated filter changed color in response to Salmonella Typhimurium and Escherichia coli but not to Listeria innocua. The time required for color change of pPCDA-coated filters was determined by a visual panel. A simple linear regression model was generated to fit the observed data and was validated with goodness of fit analysis and residual analysis. The pPCDA-filter method estimated Salmonella Typhimurium populations of 8 to 3 log CFU ml-1 within 1.5-7.5 h, respectively.

Single-crystal X-ray diffraction dataset for 3,5-difluoro-2,6-bis(4-iodophenoxy)-4-phenoxypyridine.

The data in this article are related to the research article "Utilizing the Regioselectivity of Perfluoropyridine towards the Preparation of Phenyoxyacetylene Precursors for Partially Fluorinated Polymers of Diverse Architecture."1 The X-ray structure analysis of 3,5-difluoro-2,6-bis(4-iodophenoxy)-4-phenoxypyridine has revealed an asymmetric unit containing two molecules, linked via both Type I and Type II C-I∙∙∙I-C halogen bonding interactions. The packing is further consolidated via Ar-H∙∙∙π interactions. This compound has been utilized for the synthesis of monomers for linear and network polymers.

Superior Capsular Reconstruction With Arthroscopic Rotator Cuff Repair in a "Functional Biologic Augmentation" Technique to Treat Massive Atrophic Rotator Cuff Tears.

Surgical treatment of patients with massive rotator cuff tears is unpredictable because of a low healing rate and high incidence of clinical failure. Arthroscopic superior capsular reconstruction has emerged as a promising technique in treating younger, active patients with massive irreparable rotator cuff tears. Superior capsular insufficiency has been theorized to be a factor in the higher failure rate for repairs of massive tears, and there have been proposals of superior capsular repair in addition to rotator cuff repair to facilitate better healing of massive rotator cuff tears. This article presents our technique of functional rotator cuff augmentation, which is concomitant superior capsular reconstruction with arthroscopic rotator cuff repair, to treat massive, atrophic rotator cuff tears. This technique is used in patients with massive rotator cuff tears and superior capsular insufficiency.

Arthroscopic Superior Capsular Reconstruction With Acellular Dermal Allograft Using Push-In Anchors for Glenoid Fixation.

Massive irreparable rotator cuff tears in the younger, active patient can be one of the most challenging pathologies to treat in shoulder surgery. Over the last few years, the superior capsular reconstruction (SCR) technique, which has shown favorable initial clinical results, has emerged as a promising new technique that aims to restore glenohumeral mechanics and improve patient function. SCR can be technically challenging, and improvements have been made consistently to the technique. In this Technical Note, we present our knotless technique of glenoid fixation using push-in anchors and suture tapes. We believe that our procedure offers an improvement to current SCR techniques.

Arthroscopic Superior Capsular Reconstruction With Acellular Dermal Allograft for the Treatment of Massive Irreparable Rotator Cuff Tears: Short-Term Clinical Outcomes and the Radiographic Parameter of Superior Capsular Distance.

PURPOSE: This outcome analysis presents 88 consecutive shoulders presenting with irreparable rotator cuff tears that we treated with arthroscopic superior capsular reconstruction (SCR) using an acellular dermal allograft. We also present the concept of superior capsular distance to quantitatively measure the decreased distance present upon restoration of superior capsular integrity. METHODS: A retrospective review was conducted of patients treated with arthroscopic SCR with a minimum 12-month follow-up. Outcome analysis was performed via an internet-based outcome-tracking system to evaluate visual analog scale (VAS) and American Shoulder and Elbow Surgeons (ASES) scores. Radiographic analysis of anteroposterior radiographs analyzed acromiohumeral interval and superior capsular distance. Digital dynamometric strength and functional range of motion assessments were also obtained. The main inclusion criteria for patients in this analysis was all patients who underwent superior capsular reconstruction during the time period of this report. RESULTS: Eighty-six patients with an average age of 59.4 years presented with massive rotator cuff tears (Cofield >5 cm). Outcome data revealed improvement in VAS (4.0-1.5), and ASES (52-82) scores at 1 year (P = .005). Radiographic analysis showed increase in acromiohumeral interval (mean 7.1 mm preoperatively to mean 9.7 mm at 1 year) (P = .049) and superior capsular distance (mean 52.9 mm preoperatively to mean 46.2 mm at 1 year) (P = .011). Strength improved significantly (forward flexion/abduction/external rotation of 4.8/4.1/7.7 lb preoperatively to 9.8/9.2/12.3 lb at 1 year) as well as range of motion (forward flexion/abduction of 120°/103° preoperatively to 160°/159° at 1 year) (P = .044/P = .007/P = .02). At follow-up, 90% of patients were satisfied. CONCLUSIONS: This analysis reveals that arthroscopic SCR with acellular dermal allograft has been successful in decreasing pain and improving function in this patient subset. Radiographic analysis has also shown a consistent and lasting decrease in superior capsular distance and increase in acromiohumeral interval, indicating maintenance of superior capsular stability. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Trifluoromethylation of perfluorinated diacylfluorides: synthesis of the diketone CF3C(O)CF2C(O)CF3 and of new perfluorinated diol (CF3)2C(OH)CF2C(OH)(CF3)2.

Perfluoromalonyl difluoride reacts with TMS-CF3 (1:1) in the presence of KF to give the new diketone CF2(C(O)CF3)2. A large excess (5:1) of TMS-CF3 results in the presumed potassium dialkoxide [(CF3)2COK]2CF2 which yields the 1,3-ditertiarydiol [(CF3)2C(OH)]2CF2 on reaction with H2SO4.

Comparative analysis of single-row versus double-row repair of rotator cuff tears.

PURPOSE: Our goal in this analysis was to compare clinical outcomes and radiographic healing rates of double-row (DR) transosseous-equivalent versus single-row (SR) Mason-Allen configuration (MAC) arthroscopic repair techniques. METHODS: A prospective, nonrandomized assessment of 132 arthroscopic rotator cuff repair patients included 78 SR repair patients and 54 with DR repair. Tears measured between 1.5 and 4.5 cm. Patients were evaluated with a visual analog scale; University of California, Los Angeles score; American Shoulder and Elbow Surgeons score; active range of motion; and dynamometric strength. Scores and measurements were obtained preoperatively and at 3, 6, 12, and 24 months postoperatively. The SR repairs were performed with the arthroscopic MAC. For DR repairs, two 5.5-mm fully threaded Bio-Corkscrew anchors (Arthrex, Naples, FL), single loaded with FiberWire (Arthrex), were used for the medial row. The lateral row was secured with PushLock bioabsorbable anchors (Arthrex). Forty-four patients in the SR group and 37 patients in the DR group returned for magnetic resonance imaging (MRI) evaluation of repair integrity between 12 and 28 months postoperatively. RESULTS: DR repairs resulted in higher outcome scores, though not significantly. Patient satisfaction rates were 95% in the SR group and 92% in the DR group. MRI showed a statistically significantly improved healing rate with SR repair compared with DR repair in our entire patient population (P ≤ .017). A more homogeneous subset of patients with tears between 2.5 and 3.5 cm showed a significantly improved healing rate for the DR repair (P ≤ .03). CONCLUSIONS: Our short-term results suggest that SR MAC repair provides comparable clinical results to DR repair. Although our MRI data suggest improved healing rates in our SR repairs in the entire patient population, when similar-sized tears were compared, the DR repair group showed improved radiographic healing. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Arthroscopic posterior labral repair in athletes: Outcome analysis at 2-year follow-up.

PURPOSE: The purpose of this outcome analysis was to evaluate the clinical presentation of isolated posterior labral tears resulting from athletic injury and to use multiple outcome measurements to evaluate postoperative results after arthroscopic repair with respect to satisfaction, function, and return to sport. METHODS: Seventy-five consecutive patients injured during athletic activity were treated surgically during the 2-year period from 2005 to 2006 for labral pathologies. Twenty-eight patients were treated for isolated posterior labral tears. Of these, all underwent arthroscopic repair of their tears. The mechanism of injury was trauma to a previously asymptomatic shoulder during sports. The patients' mean age was 21 years, and they were evaluated with American Shoulder and Elbow Surgeons; University of California, Los Angeles; Rowe; and visual analog scale scores, as well as active motion and dynamometric strength testing. Scores and measurements were obtained preoperatively and postoperatively at 3, 6, and 12 months and yearly thereafter. RESULTS: In our athletic population undergoing surgical management for labral pathology, 37% of patients (28 of 75) were found to have purely posterior labral lesions after an athletic injury. On intraoperative examination, an element of posterior laxity was seen in only 29% of patients with these tears. At 24 months, significant improvements were observed in the American Shoulder and Elbow Surgeons; University of California, Los Angeles; Rowe; and visual analog scale scores. Increases in forward flexion and external rotation strength were also noted. Return to sport was achieved in 26 of 28 patients (93%). A 93% patient satisfaction rate was observed for arthroscopic posterior labral repairs at more than 24 months. CONCLUSIONS: Our patient-athletes presented with painful, dysfunctional shoulders that inhibited performance in their chosen sport. Arthroscopic evaluation and repair of these posterior labral lesions resulted in 26 of 28 patients (93%) returning to sport and 23 of 28 (82%) returning without any limitations. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Complementary halogen and hydrogen bonding: sulfur...iodine interactions and thioamide ribbons.

Complementary halogen bonding and hydrogen bonding coexist in co-crystals of organoiodines with molecules containing the thioamide functionality. Thiourea.organoiodine co-crystals are shown to exhibit a remarkably reliable synthon with complementary N-H...S ribbons and S...I interactions.