RE: Is "Vibrational Spectroscopy" generally equals to "IR spectro scopy"?

My own opinion only:
 In practice "vibrational spectroscopy" is generally synonymous with
 "IR
 spectroscopy."  However, there is a reason for having the 2 terms, since
 they are not *precisely* synonymous, and different concepts are involved in
 the 2 terms even if in practice the spectra being discussed are the same.
 "Vibrational" spectroscopy refers to the method in which the substance
 gains
 energy as a result of absorption: the energy goes largely into nuclear
 motions which involve changing of bond lengths & angles.  "IR" (=
 "infrared") spectroscopy refers to the frequencies of electromagnetic
 energy
 being absorbed.
 As for "absorption" spectroscopy (I expect "adsorption" is a
 mistake, since
 I still get those words mixed up on occasion myself :-), this is an entirely
 separate issue.  Absorption spectroscopy means that material is gaining
 energy at the expense of the electromagnetic field; emission spectroscopy
 means that the material is emitting energy as electromagnetic radiation.
 --David Shobe
 S?-Chemie Inc.
 phone (502) 634-7409
 fax     (502) 634-7724
 email  dshobe "-at-" sud-chemieinc.com
 Don't bother flaming me: I'm behind a firewall.
 -----Original Message-----
 From: Zhenhua Li [mailto:lbbg123 "-at-" etang.com]
 Sent: Wednesday, January 16, 2002 11:37 PM
 To: chemistry "-at-" ccl.net
 Subject: CCL:Is "Vibrational Spectroscopy" generally equals to
 "IR
 spectroscopy"?
 Hi, Dear listers,
 Today several staffs have a discussion about what is the implied or
 generally accepted meaning of "vibrational spectroscopy". One guy
 insisted
 that it is generally accepted that when we talked about vibrational
 spectroscopy, without specify IR or Raman before it, we must say that it is
 an "adsorption spectroscopy".  But I insisted that any spectroscopy
 that
 originated from vibrational adsorption or emission can be called
 "vibrational spectroscopy". Thus, when we talked about
 "vibrational
 spectroscopy", we do not really means it is an IR spectroscopy.
 This is important since the meaning of this term has appeared in an exam
 paper. It is important to ensure not to give students wrong concept.
 Thanks a lot.
 Li Zhenhua
 -= This is automatically added to each message by mailing script =-
 CHEMISTRY "-at-" ccl.net -- To Everybody  | CHEMISTRY-REQUEST "-at-" ccl.net --
 To Admins
 MAILSERV "-at-" ccl.net -- HELP CHEMISTRY or HELP SEARCH
 CHEMISTRY-SEARCH "-at-" ccl.net -- archive search    |    Gopher: gopher.ccl.net
 70
 Ftp: ftp.ccl.net  |  WWW: http://www.ccl.net/chemistry/   | Jan: jkl "-at-" ccl.net