A new polymorph of N-(prop-2-yn­yl)tricyclo­[3.3.1.13,7]decane-1-carbox­amide

The alkynyl bond of the title compound, C14H19NO, has a length of 1.170 (5) Å. The amide function shows a trans conformation with respect to the carbonyl group characterized by the torsion angle O—C—N—H of −176 (2)°. There is an inter­molecular N—H⋯O hydrogen bond between the amide function and the carbonyl group. In addition, weak inter­molecular hydrogen bonds stabilize the crystal structure. A comparison with a polymorphic structure shows conformational differences with regard to the orientation of the carbonyl groups with respect to the adamantyl group [O—C—C—C = 96.2 (3)° in the title compound and 123.7 (2)° in the polymorph] and the orientations of the propargyl groups in relation to the carbonyl groups [O—C—C—C = −87.7 (3) and −58.7 (2)°, respectively]

Chlorido[3,3′-dibutyl-5,5′-(pyridine-2,6-di­yl)dipyrazol-1-ido]gold(III)

The Au atom in the C2-symmetric pincer-type title complex, [AuCl(C19H23N5)], is in the +3 oxidation state. The ligand is composed of one pyridine unit and two n-butyl-substituted pyrazoles (pyrz). Both pyrazoles are deprotonated, thus forming a neutral compound. To the best of our knowledge, this is the first AuIII–bis­pyrazolate complex. According to the special geometry in the N,N′,N′′-tridentate ligand, containing two five-membered heterocycles, the complex deviates from an ideal square-planar coordination geometry; the Npyrz—Au—Npyrz angle is 160.8 (3)°, indicating a distortion of nearly 20°

(Sp)-1-Diphenylphosphanyl-2-{(S)-[2-(diphenylphosphanyl)phenyl]hydroxymethyl}ferrocene

The absolute configuration of the title compound, [Fe(C5H5)(C36H29OP2)], is Sp at the ferrocene group and S at the asymmetric C atom. Both P atoms have a trigonal-pyramidal conformation. There is a short intramolecular C-H...P contact with an H...P distance of 2.56 Å. The hydroxy group is involved in an intramolecular O-H...[pi]phenyl interaction. The crystal packing shows five very weak intermolecular C-H...[pi] contacts, with H...Cg distances between 3.26 and 3.39 Å (Cg is the centroid of a phenyl or cyclopentadienyl ring). Key indicators: single-crystal X-ray study; T = 162 K; mean σ(C–C) = 0.004 Å; R factor = 0.038; wR factor = 0.083; data-to-parameter ratio = 22.3

Slowing light through Zeeman Coherence Oscillations in a duplicated two-level system

We present the theory of a new method to slow a linearly polarized probe pulse as it propagates through a duplicated two-level system driven by an orthogonally polarized control field. The method makes use of Zeeman coherence oscillations (CZO) that arise in the atomic system because of the spatial and temporal modulation of the total polarization. This method exhibits properties similar to those that rely on the electromagnetically induced transparency (EIT) but without the existence of any trapping state. We demonstrated also the propagation of a dark polariton in the mediumComment: Rapid communication in PRA, 4 pages, 3 figures. Phys Rev A, rapid com. accepted (2008

Homogeneous Gold Catalysis through Relativistic Effects: Addition of Water to Propyne

In the catalytic addition of water to propyne the Au(III) catalyst is not stable under non-relativistic conditions and dissociates into a Au(I) compound and Cl2. This implies that one link in the chain of events in the catalytic cycle is broken and relativity may well be seen as the reason why Au(III) compounds are effective catalysts.Comment: 12 pages, 3 figures, 1 tabl

Papillary thyroid carcinoma formation in a thyroglossal cyst. A case report

Thyroglossal cyst rarely presents with carcinoma formation in the remnants of the thyroid gland. We report a 40 year old male with papillary thyroid carcinoma formation in a thyroglossal cyst. The patient underwent surgical intervention for the cyst. His pathology was positive for thyroid carcinoma and he underwent complete thyroidectomy with postoperative radioactive iodine treatment. His follow up revealed no evidence of recurrence