UV-vis and IR spectroscopic studies of some 4-arylhydrazo-2-phenyl-2-oxazoline-5-one derivatives

The absorption spectra of some 4-arylhydrazo-2-phenyl-2-oxazoline-5-one derivatives, have been studied in organic solvents of different polarity. The diagnostic IR spectral bands are assigned and discussed in relation to molecular structure and hydrogen bond existing in the stable compounds in the hydrazo form. The presence of electron withdrawing group in the phenyl ring facilitates the charge migration and hence the proton transfer, thus the azohydrazo form may appear in these compounds, but the major compounds were in the hydrazo form. The fact that these compounds show evidence for intramolecular hydrogen bonding is in favor of the hydrazone structure, this fact excludes the possibility of azo structure. The electronic absorption bands are assigned to the corresponding electronic transitions and the effect of solvent parameters on the charge transfer energy [ECT] is investigated. Four absorbance bands appeared for hydrazones in the range 443-221 nm, the first band has Amax within the range 222-237 nm corresponding to the medium energy transition of the phenyl group e [1]La-[1]A]. The second band with [lambda]max at 243-257 nm is attributed to the low energy mm transition of the phenyl rings representing the [[1]Lb-[1]A] electronic state. The third band at 278-314 nm lies within the energy region for the mm excitation of the electrons of the hydrazo groups. The last band in the visible which has [lambda]max within the range 422-443 nm is considered as being due to an intramolecular charge transfer involving the whole molecule. Finally, the substitution effect was also studied

Adsorption of phenol and some substituted phenols on chemically - activated carbons developed from apricot stones

Chemically activated carbons were prepared from apricot stones. Phosphoric acid [25 - 75 wt%] was used as activating agent at 400 - 600 °C. Zinc chloride - activated carbons were also prepared at 600 °C and at 700 °C using zinc chloride [50 - 200 wt%] as activating agent. The textural parameters were determined from nitrogen adsorption data at 77 K. The chemistry of the carbon surfaces was determined from the FTIR spectrograms and from the base and acid neutralization capacities. The adsorption of phenol, p -nitrophenol and 3,5-dinitrophenol was carried out at 298 K for all the prepared carbons and also at 308 and 317 K for some selected carbons. Chemically - activated carbons exhibited high adsorption capacity towards phenols. Phenols adsorption increased with the increase of the molecular weight of the phenol and with the decrease of its solubility in water. The adsorption of phenols increased also with the decrease of the surface density of carbon - oxygen group existing. Adsorption of phenols proceeds via physical adsorption on oxygen - free surface and via chemisorption on oxygen contaminated carbon surfaces. Activated carbons [AC's] are widely used as adsorbents in decontamination process because of their extended surface area, microporous structure high adsorption capacity and special surface reactivity[1-4]. The surface of AC is considered heterogeneous from the point of view of both porosity and surface chemistry. The heterogeneity of the pore structure is a result of the existence of a wide range of size from a few to a few hundred angstroms[5]. The heterogeneity of the chemistry of AC is attributed to the existence of heteroatoms such as oxygen, nitrogen, hydrogen and phosphorous[6-7]. The heteroatoms, particularly oxygen, consist of organic functional groups at the edges of carbon crystallites. Carbon-oxygen groups include carboxyls, phenols, ethers, lactones and carbonyl[8]. There has been an increasing interest in the study of adsorption of organic molecules on AC. This is due to the importance of the removal of organic pollutants from water streams and the atmosphere[9]. Adsorption of aromatic compounds from solution, particularly phenols, has been studied extensively[10-14]. Phenolic compounds exist widely in the industrial effluents such as those from oil refineries, cool tar, leather, paint, pharmaceutical and steel industries. Since they are highly toxic and, in general, not amenable to biological degradation, methods of treatment are continuously modified and developed at all treatments. Among adsorbents, granular or powder AC proved to be the most efficient[15-19]. Regardless of the enormous studies undertaken concerning the adsorption of phenols on carbon, it can be seen that more intensive investigations still need to be undertaken to find convincing answer for some problems still remaining on phenol uptake by AC. The objective of this paper is to study the effect of surface chemistry and surface area of carbons on their adsorption of phenols. The samples are different from the point of view of the activating agent used [Zinc chloride and phosphoric acid]. An important feature common for all the samples is their acidic surface pH. Under such condition phenols exist in their molecular form. Three phenols were studied, namely phenol [P], paranitrophenol [PNP] and dinitrophenol [DNP]

Synthesis of polyfunctionally substituted 5,6,7,8 tetrahydroquinolines and several condensed azines

2-amino-3-cyano-4-phenyl-5,6,7,8-tetrahydroquanoline [3] and other related new quinolones were synthesized and submitted to evaluation for their anti-microbial activity. Compound [3] was prepared by reaction of cyclohexanone, arylidines malononitrile and amm. acetate. Other reagents were studied as the nature of the nuceolophile and reaction conditions. The behaviour of some products towards carbon electrophiles, e.g. acid chlorides, acid anhydrides and alkylating agents has been discussed

Effects of drinking a glass of water two hours before operation

This work was designed depending on the studies on gastric physiology which proved that, fluid load 80% of the stomach contents is cleared within the 1st hour. Drinking a glass of water [200 ml] 2 hours before operation was compared to overnight fasting in children scheduled for tonsillectomy. 60 patients, ASA I, of both genders, ages 5 to 15 years were classified into 2 equal groups. Groups were compared as regards pH and volume of gastric fluid, sense of thirsty, and anxiety through a prospective, randomized, single-blind study. There were no significant changes in pH and volume of gastric fluid between the 2 groups. There was highly significant decrease in the number of patients suffering from thirsty in the group received water [P <0.001]. The number of anxious patients and the degree of anxiety was less in patients who drank water, but the difference was statistically insignificant. Thus, it was recommended to give a glass of water 2 hours before operation to school age children going for elective surgery, as it does not affect gastric pH and volume and it makes the patient less thirsty and less anxious

comparative study on the effect of administration of fentanyl before [Thiopentone, ketamine and propofol] on the haemodynamic response to tracheal intubation

The haemodynamic response to tracheal intubation was compared in 300 patients in whom anaesthesia was induced with either Thiopentone 4 mg/kg. Ketamine 2 mg/kg or Propofol 2.5 mg/kg. with and without Fentanyle 2 ug/kg. There was, after Propofol alone, a significant decrease in arterial blood pressure which did not increase above control values after intubation. Significant increases in arterial blood pressure followed intubation in patients induced with Thiopentone or Ketamine alone. Increase in heart rate occured with all agents after laryngoscopy. The use of Fentantle resulted in arterial pressure lower than those after the induction agent alone and in an attenuation, but not abolition of the response to laryngoscopy and intubation

comparative study of caudal morphine or ketamine for post-operative analgesia in children

In a randomized double-blind study of 30 children [aged 18 months - 6 yr.] pain following herniotomy was releived with a caudal injection of either 0.1 mg kg - 1 morphine or 0.5 mg kg -1 ketamine with normal saline 1 ml. kg. -1. There was no significant difference in post-operative behaviour or analgesic requirements between two groups. The morphine group provided better analgesia than the Ketamine group. Side effects such as urinary retention, vomiting, respiratory depresion were minimal in both groups

comparative study on the effect of administration of fentanyl with [thiopentone or propofol on intra-ocular pressure changes during induction and intubation]

Intraocular pressure was measured durning induction of anaesthesia with propofol [n=40] or thiopentone [n=40]. The average induction dose were 2.15 and 4.83 mg Kg [-1] for propofol and thiopentone. Half the patients in each group received 100 ug Fentanyl with thiopentone and propofol. Both propofol and thiopentone produced a significant reduction in intraocular pressure which decreased further after administration of Fentanyl. Intraocular pressure prior to intubation was lower in the two propofol groups in comparison to the corresponding thiopentone groups. Intubation was associated with an increase in intraocular pressure but it still remained significant below the baseline values except in the group given thiopeentone only. Fentanyl given with the induction agents attenuate the increase in intraocular pressure associated with intnbation. Propofol was significantly more effective in this respect and this group showed the lowest intraocular pressure throughout the study period. However, administration of popofol resulted in a 30% incidence of pain on injection and a decrease in systolic arterial pressure of more than 30% in about half the patients [most of them in the group that received fentanyl with propofol]

Prevention of tourniquet pain by spinal isobaric bupivacaine with morphine

In order to asses the effect of spinal morphine on tourniquet pain, 30 patients scheduled to undergo orthopedic surgery under spinal anaesthesia were allocated randomly to two groups. Patients in group I [N=15] received 0.5% isobaric bupivacaine 15 mg plus isolated saline 1 ml. Patients in group II [N=15] received 0.5% bupivacaine 15 mg plus morphine 1 ml [0.3 mg]. Sensory block was evaluated by pinprick and motor block with Bromage's scale. The presence of moprhine significantly prolonged the duration of sensory and motor block. Three patients in group I, but none in group II, experienced tourniquet pain. Hypotension and bradcardia were not worsened by spinal morphine. The use of morphine may be a useful technique to augment bupivacaine spinal block