Bis(9-amino-acridinium) bis-(pyridine-2,6-dicarboxyl-ato-κO,N,O)nickelate(II) trihydrate.

The title compound, (C(13)H(11)N(2))(2)[Ni(C(7)H(3)NO(4))(2)]·3H(2)O, consists of a mononuclear anionic complex, two 9-amino-acridinium cations and three uncoordinated water mol-ecules. Two pyridine-2,6-dicarboxyl-ate (pydc) ligands are bound to the Ni(II) ion, giving an NiN(2)O(4) bonded set. The coordination geometry around the Ni(II) atom is distorted octa-hedral. There are two types of robust O-H⋯O hydrogen-bond synthons, namely R(6) (6)(24) and R(2) (4)(8), which link the complex anions and water mol-ecules to each other. N-H⋯O hydrogen bonds connect the stacks of anions and cations in the structure. Other inter-molecular inter-actions, including weak C-H⋯O hydrogen bonds, π-π [shortest centroid-centroid distance = 3.336 (7) Å] and C-O⋯π [O⋯centroid distance = 3.562 (10) Å] inter-actions, connect the various components

Cyanobacterial metabolites as a source of sunscreens and moisturizers: a comparison with current synthetic compounds

The recognition that ultraviolet radiation has harmful effects on the skin has led to the commercial development of inorganic and synthetic organic UV filters that can reduce the negative effects of exposure to sunlight. In addition, moisturizing chemicals are extensively used in personal care products to improve the ability of skin to retain water. Whilst current UV filter and moisturizing chemicals have clear beneficial qualities, they may also have adverse effects such as contact sensitivity, oestrogenicity and even tumorigenic effects on human skin. Furthermore, the accumulation of these chemicals in the aquatic environment could be potentially harmful. Consequently, there is interest in exploiting safer alternatives derived from biological sources, especially from photosynthetic organisms such as cyanobacteria which have developed mechanisms for coping with high UV irradiation and desiccation. In order to overcome the detrimental effects of UV radiation, these microorganisms produce UV screening compounds such as mycosporine-like amino acids and scytonemin, which are good candidates as alternatives to current synthetic UV filters. In addition, extracellular substances produced by some extremophilic species living in hyper-arid habitats have a high water retention capacity and could be used in cosmetic products as moisturizers. In this review, we present an overview of the literature describing the potential of cyanobacterial metabolites as an alternative source for sunscreens and moisturizers

Bis(2,9-dimethyl-1,10-phenanthrolin-1-ium) hydrogen (S,S)-tartrate nona­hydrate

The asymmetric unit of the title compound, 2C14H13N2 +·2C4H5O6 −·9H2O, contains two cations and two anions in addition to nine mol­ecules of water. Each of the hydrogen tartrate anions is hydrogen bonded to itself by translation along [100] in a head-to-tail fashion via a short hydrogen bond with donor–acceptor distances of 2.473 (4) and 2.496 (4) Å. A large number of inter­molecular O–H⋯O, N—H⋯O and C–H⋯O hydrogen-bonding inter­actions, as well as π–π stacking [centroid–centroid distances in the range 3.642 (3) to 3.866 (3) Å], play an important role in the crystal structure

Acridinium 3-carb­oxy­pyrazine-2-carboxyl­ate

The title ion pair, C13H10N+·C6H3N2O4 −, contains a protonated acridine cation and a 3-carb­oxy­pyrazine-2-carboxyl­ate monoanion, which are linked together through O—H⋯O, N—H⋯O and weak C—H⋯O hydrogen bonds. These hydrogen bonds generate a C(10) chain graph-set motif. The crystal structure is further stabilized by extensive π–π stacking inter­actions between nearly parallel [dihedral angle = 1.21(2)°] acridine systems. The shortest distance between the centroids of the six-membered rings within the cations is 3.6315 (8) Å. In addition, C—H⋯π edge-to-face inter­actions are present

Tetrameric DABCO™-Bromine: an Efficient and Versatile Reagent for Bromination of Various Organic Compounds

Tetrameric DABCO™-bromine is a powerful brominating agent but shows reasonable selectivity with certain substrates. The selective bromination for activated aromatic compounds and alkenes is reported. Synthesis of -bromo ketones and nitriles has also been achieved by using this reagent and the results are also reported. All products reported were obtained in good to excellent yields.KEYWORDS: Tetrameric DABCO™-Bromine, TDB, solid supports, bromination, -bromination, 1,2-dibromo compounds, bromohydrin

Bis(9-amino­acridinium) bis­(pyridine-2,6-dicarboxyl­ato)cuprate(II) trihydrate

The asymmetric unit of the title compound, (C13H11N2)2[Cu(C7H3NO4)2]·3H2O, consists of one [Cu(pydc)2]2− dianion (pydc is pyridine-2,6-dicarboxyl­ate), two 9-amino­acridinum monocations and three uncoordinated water mol­ecules. The CuII atom is coordinated by two pydc dianions acting as tridentate ligands, and forming five-membered chelate rings with copper(II) as the central atom. The CuII atom is surrounded by four O atoms in the equatorial plane and two pyridine N atoms in axial positions, resulting in a distorted octa­hedral coordination geometry. In the crystal, there are two types of O—H⋯O and N—H⋯O hydrogen-bonding synthons linking the anionic and cationic fragments and the water mol­ecules, namely R 4 4(16), and R 4 2(8). There are also weak C—H⋯O hydrogen bonds, π–π stacking inter­actions [the shortest centroid–centroid distance is 3.350 (2) Å], and a C—O⋯π inter­action [O⋯centroid distance = 3.564 (2) Å], which connect the various components into a three-dimensional network

Acridinium 3,5-dicarboxy­benzoate monohydrate

The title compound, C13H10N+·C9H5O6 −·H2O, exhibits a wide range of non-covalent inter­actions, such as O—H⋯O and N—H⋯O hydrogen bonds, π–π stacking [centroid-centroid distances = 3.562 (8) and 3.872 (8) Å] and ion pairing, connecting the various components into a supra­molecular structure

Acridinium 6-carb­oxy­pyridine-2-carboxyl­ate monohydrate

The title compound, C13H10N+·C7H4NO4 −·H2O or (acrH)+(pydcH)−·H2O, is a monohydrate of acridinium cations and a mono-deprotonated pyridine-2,6-dicarb­oxy­lic acid. The structure contains a range of non-covalent inter­actions, such as O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds, as well as π–π stacking [range of centroid–centroid distances = 3.4783 (5)–3.8059 (5) Å]. The N—H⋯O hydrogen bond between the donor acridinium cation and the carboxyl­ate acceptor is particularly strong. The average separation between the π-stacked acridinium planes is 3.42 (3) Å

The Versatility of 980 nm Diode Laser in Dentistry: A Case Series

Introduction: Laser surgery has been considered a popular alternative over conventional modalities in dentistry during the last few years. Among different types of lasers, diode lasers have gained special attention in oral soft tissue surgery.Case Reports: Five patients were referred to a private office. After careful evaluation of medical history and oral examination, oral diagnosis and treatment plan of each patient was established as follows: (1) A 21-year-old female with ankyloglossia (tongue-tie); (2) A 65-year-old female with a poor denture fit needing vestibuloplasty and frenectomy; (3) A 10-year-old male patient with pigmented gingiva in mandible and maxilla; (4) A 14-year-old female needing exposure of maxillary right canine for bracket bonding; and (5) A 25-year-old female patient who has a gingival maxillary frenum with a nodule. The treatment plan for all the patients was laser surgery with diode laser at 980 nm, in continuous mode.Results: All the patients experienced normal healing process with no postoperative complications. Favorable outcomes of laser surgery were observed on follow-up sessions.Conclusion: Considering the versatility of the 980 nm diode laser in oral soft tissue surgeries and the advantages of laser surgery, this study suggests the use of 980 nm diode laser in this regard