| abstract |
(57) The present invention provides compounds having Formula (I) or Formula (II), wherein R 1 is selected from halogen and an organic moiety; R 2 and R 3 are hydrogen and Independently selected from organic moieties having a mass greater than 15 daltons; Z is an (n + 1) valent atom excluding carbon; R 4 is selected from hydrogen, halogen and organic moieties having a mass greater than 15 daltons R 5 in each occurrence is independently either halogen or an organic moiety having a mass of less than 500 daltons; m is selected from 0, 1, 2, 3, and 4; ) And (II) are present in a mixture, the molar ratio of formula (I): formula (II) in the mixture is other than 50:50. This compound is useful as a label including a label that can be detected by mass spectrometry. |