It seems that you are confusing eloquence with verbosity. Eloquence is finding the best possible combination of words to express meaning (e.g. masters of the Haiku). Verbosity involves using large words or too many words to express meaning. Your habit appears to be using long strings of mid-level words in confusing syntax. Since you aren't regularly using truly difficult words (judging by your post) in a natural way, you don't appear intelligent, instead coming off as an asshat to your coworkers. Incidentally, using larger words in unnatural ways one step of the vocabulary building process according to Johnson O'Connor's theories enumerated in his English Vocabulary Builder. It may very well be that you will "grow into" your larger vocabulary, but as it is, I would suggest not attempting to sound overly articulate.