Structural and substituent effects on the ketene infrared stretching frequency

Substituent effects on structural stability of formyl ketene and analysis of vibrational spectra of formyl haloketenes and formyl methylketene.

The conformational behavior and the structural stability of formyl fluoroketene, formyl chloroketene and formyl methylketene were investigated by utilizing quantum mechanical DFT calculations at B3LYP/6-31I + + G** and ab initio calculations at MP2/6-311 + + G** levels. The three molecules were predicted to have a planar s-cis<-->s-trans conformational equilibrium. From the calculations, the di...

the effects of planning on accuracy and complexity of iranian efl students’ written narrative task performance

this study compared the different effects of form-focused guided planning vs. meaning-focused guided planning on iranian pre-intermediate students’ task performance. the study lasted for three weeks and concentrated on eight english structures. forty five pre-intermediate iranian students were randomly assigned to three groups of guided planning focus-on-form group (gpfg), guided planning focus...

the effects of speech rate,prosodic features, and blurred speech on iranian efl learners listening comprehension

کلید واژه ها به زبان انگلیسی: effect of speech rate on listening comprehension, blurred speech,segmental and suprasegmental features,authentic speech,intelligibility, discrimination, omission, assimilation چکیده: سرعت مطالب شنیداری در کلام پیوسته بطور کلی همواره کابوسی بوده برای یادگیرنده های زبان دوم و بالاخص برای شنوندگان ایرانی. علی رغم عقل سلیم که کلام با سرعت کندتری فعالیتهای درک مطلب شن...

the effects of cooperative versus individual directed reading thinking activities on students inferential and referential questions

two groups of students were assigned as experimental and control ones, and were given instruction on directed reading-thinking activities and after some treatment, they were post-tested. although the initial pre-test did not show any significant differences, the final post-test result revealed that the cooperative reading comprehension helped the experimental group. the cooperative students’...

Substituent effect on c-f stretching frequency in substituted aryl fluorides