Novel 2-benzothiazole-, 4-pyridine-, and 2- and 4-quinoline-based styryl dyes containing an N-methylbenzoaza-15(18)-crown-5(6)-ether moiety were synthesized. A detailed electronic spectroscopy study revealed high performance of these compounds as optical molecular sensors for alkali and alkaline-earth metal cations. They were shown to considerably surpass analogous chromoionophores based on N-p...

The two new ozonide compounds K([12]crown-4)2O3 · 1.5 NH3 (1) and Rb([12]crown-4)2O3 · 1.5 NH3 (2) were synthesized from the binary alkali metal ozonides and [12]crown-4 in liquid ammonia. The airand temperature-sensitive red, needle-shaped compounds crystallize isostructurally in the non-centrosymmetric space group Fdd2 (no. 43) with 16 formula units per unit cell. The lattice parameters are a...

In this clinical study, 19 full metal crown restorations of canine teeth were placed in seven working dogs. Thirteen canine teeth were severely abraded with no involvement of the pulp cavities; six fractured canine teeth were endodontically treated. At least 1/3 of the coronal part of the canine tooth was available for a supragingivally performed, minimal tooth crown preparation. An adhesive te...

The asymmetric unit of the title cocrystal, [Sn(CH(3))(C(6)H(5))Cl(2)(H(2)O)(2)]·C(10)H(20)O(5), contains two independent for-mula units. The organotin molecules exhibit a six-coordinate metal atom and are linked to the crown ether molecules by water-crown ether O-H⋯O hydrogen bonds into a linear chain running along [101]. Each coordinated water mol-ecule forms a pair of hydrogen bonds to the s...

Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the larg...

A series of adamantane functionalized diaza-lariat ethers 1–6 have been prepared and alkali metal picrate extraction profiles determined. The ability of aza-crown ethers 1–6 to extract the alkali metal picrates was compared with that of diaza-18-crown-6 (7) and N,N '-dibenzodiaza-18-crown-6 (8). Na and K transport across bulk liquid membrane was also measured. The results of alkali metal cation...

always on kingdom history of the world a king without a crown is unconceivable. the persian kings were not exception of this rule. iranian ancient kings crown as one of the aspects of the monarchy and power, the image of king while makes he distinguishes from other persons is visible in various artistic works. one of the important artistic works that image of iran’s kings with their power symbo...

The synthesis of novel magnesium, copper, and metal-free porphyrazines, peripherally substituted with dithia-7-crown-2 (MPz(7)), dithia-15-crown-5 (MPz(15)), and dithia-18-crown-6 (MPz(18)) macrocycles is reported. These compounds are prepared starting from dicyanoethylene containing crown ethers 3, 2(1), and 2(2), respectively, which contain sulfur as well as oxygen heteroatoms. The "crowned" ...

Complicated crown-root fractures are rare and often need complex treatment planning. This case report describes the management of an oblique crown-root fracture of maxillary right central incisor. Endodontic treatment of the tooth was performed and the tooth was provisionally restored. The tooth was then orthodontically extruded by 2 mm to raise the defect supraginigivally. Gingivectomy was per...

STATEMENT OF PROBLEM Unresolved controversy exists concerning the remaining coronal tooth structure of anterior endodontically treated teeth and the best treatment option for restoring them. PURPOSE The purpose of this study was to evaluate the effect of post, core, crown type, and ferrule presence on the deformation, fracture resistance, and fracture mode of endodontically treated bovine inc...