Infrared Spectra of Organic Azides

Abstract

the neighborhood of the melting point of the steroid, in the hope of providing additional information on the nature of the phenomenon. SUMMARIZING REMARKSBecause deteriorated spectra are seldom observed with hand-ground preparations, it might seem preferable to forego the practical convenience of the mechanical vibrator and resort to hand grinding in the routine preparation of potassium bromide disks. How-ever, there is the problem of polymorphism to consider, and frequently, though not invariably, the vibrator technique helps to eliminate ambiguities arising from this cause.With this in mind, the authors adopted the following routine procedure for the preparation of potassium bromide disks of steroids.The steroid (2 mg.) and potassium bromide (400 mg.) are weighed successively into the capsule of the vibrator and vibrated with an agate ball for 15 minutes. The material is then transferred to the die, which is evacuated and the powder is pressed at 7 tons per sq. inch for a minimum of 3 minutes, after which the pressure and vacuum are released and the pellet is removed. The pellet is next heated at 105°for a minimum of 5 minutes. If it remains clear, its spectrum is determined.If it becomes opaque during the heat treatment, the disk is reground by hand, using a mortar and pestle, the resultant powder is repressed and the spectrum of the new disk is accepted for characterization of the compound. ACKNOWLEDGMENTThe author wishes to thank T. F. Gallagher and R Norman Jones for helpful discussion and Beate B. Spiegel for technical assistance.

Surface Doping Quantum Dots with Chemically Active Native Ligands: Controlling Valence without Ligand Exchange

“…In both free and surface-bound ligands, the asymmetric and symmetric azide stretching frequencies, ν as (N 3 ) and ν s (N 3 ), remain unchanged at 2090 and 1250 cm −1 , respectively (Figure 2b). 42 The formation of surface-doped CdS nanocrystals proceeds equally well in either 1-octadecene (ODE) or phenyl ether (Ph 2 O) as solvent. However, the olefinic resonances in ODE make it difficult to distinguish whether double bond resonances observed by NMR arise either from capping ligands or from residual ODE solvent.…”

2‐Aryl‐4‐azido‐3‐(bromo/iodo)quinolines as substrates for the synthesis of primary 4‐amino‐2,3‐disubstituted quinoline derivatives

“…We then resorted to literature method that involves displacement of chlorine at the -position of the quinoline nucleus by azide ion to form azidoquinoline derivatives under very mild conditions [7,12]. were subjected to NaN 3 in DMF at room temperature to afford the corresponding hitherto unknown 2-aryl-4-azido-3-halogenoquinoline derivatives (3a-h) (symmetric) in agreement with the literature values for organic azides [13]. There are several reagents and conditions described in literature for the reduction of azides to primary amines and these include the use of lithium aluminum hydride, sodium borohydride, sodium borohydride/ phase-transfer catalyst, catalytic hydrogenation, triethyl phosphite and electrolysis [7,14].…”

Direct Generation of Polymer Films on Copper Surfaces through Azide‐Alkyne Cycloaddition Reactions between Peptidomimetic Oligomers

“…An ATR-IR spectrum of oligomer 1 before film formation showed a characteristic peak at 2 101 cm À1 , corresponding to the azide asymmetric stretch, [25] along with the expected amide carbonyl stretching peak at 1 667 cm À1 Direct Generation of Polymer Films on Copper Surfaces through Azide-Alkyne . .…”