ABSTRACT
Herein we report the synthesis and characterisation of a series of salalen and salan ligands derived from 2-(aminomethyl)piperidine. Depending on the choice of starting salicylaldehyde, a bicyclic salan type ligand (1-3H2) or imino salalen type ligand (4-6H, 7-9H2) were prepared. The ligands were successfully complexed to group 4 metals and aluminium; with hafnium and zirconium octahedral complexes, M(1-3)2, were realised; whilst with aluminium tetrahedral and trigonal bipyramidal complexes, Al(1-9)Mex (x = 1,2), were isolated. The complexes have been characterised in solution via(1)H and (13)C{(1)H} NMR spectroscopy and in the solid state by X-ray crystallography. The group 4 complexes were observed to have a fac-fac arrangement of ligands and there were two isomers present when 3H2 was ligated. The imino aluminium complexes Al(7-9)Me were isolated as a mixture of diastereoisomers. The resultant complexes were trialed in the ring opening polymerisation of rac-lactide with both heterotactic and isotactic PLA being demonstrated. Tacticity was found to be dependent on the nature of the ligand and metal used; the M(1-3)2 complexes were generally found to have a heterotactic preference (Pr = 0.67-0.76) and the aluminium polymerisation outcome was dictated more by the steric influence of the ligand, particularly for Al(4/6)Me2/Al(7/9)Me.
ABSTRACT
OBJECTIVE: To evaluate the effectiveness of 70% isopropyl alcohol swabs in disinfecting eyelid speculums after examination for retinopathy of prematurity. METHODS: Two phases. Phase 1: 46 autoclave-sterilized eyelid speculums randomized into either a cleaned or control group following examination for retinopathy of prematurity. Speculums in the cleaned group were disinfected with a 70% isopropyl alcohol swab while control speculums were not cleaned. Bacterial and fungal cultures were then obtained. Phase 2: 20 autoclave-sterilized eyelid speculums inoculated with a clinically relevant dilution of adenovirus serotype 5 or herpes simplex virus type 2. Inoculated speculums were randomized into either a cleaned or control group. RESULTS: Phase 1: 17 (70.8%) of 24 cultures from the cleaned group yielded bacteria compared with 21 (95.5%) of 22 controls. Fungi were isolated from only 1 control and from no cleaned speculums. Phase 2: all speculums inoculated with adenovirus supported growth of the organism irrespective of cleaning with 70% isopropyl alcohol swabs. None of 5 cleaned speculums inoculated with herpes simplex virus type 2 supported viral growth, compared with 3 (60%) of 5 cultures positive for growth in the control group. CONCLUSION: Cleaning eyelid speculums with 70% isopropyl alcohol swabs provided inadequate disinfection against bacteria following examination for retinopathy of prematurity and against adenovirus in a laboratory simulation.
