The loss of homogeneity of poly(arylester) dendrimers during the matrix-assisted laser desorption/ionisation experiment is discussed. Both laser-induced fragmentation and reactions in solution before sample deposition may lead to spectra of polydisperse materials.
In our experience the abbreviation DHB is used to refer to 2,5-dihydroxybenzoic acid. However, in Reference 9 the authors state that they have used “3,5-dihydroxybenzoic acid (DHB)”.
2.
Reviewers have suggested to us that NMR and GPC data of the sample solution after 4 days, as well as variation of the pH of the solution, would have been revealing. Since we have no more dendrimer 2 we are unable to perform these interesting experiments. The generation 2 dendrimer of the same series was investigated by MALDI-TOF and 1HNMR spectroscopy, but no changes were observed in this case; in our hands larger dendrimers are more prone to the effects described herein.
3.
(a) SahotaH.S.LloydP.M.YeatesS.G.DerrickP.J.TaylorP.C.HaddletonD.M., J. Chem. Soc., Chem. Commun.2445 (1994); (b) WalkerK.L.KahrM.S.WilkinsC.L.XuZ.F.MooreJ.S., J. Am. Soc. Mass Spectrom.5, 731 (1994); (c) LeonJ.W.FréchetJ.M.J., Polymer Bull.35, 449 (1995).
4.
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5.
For two very recent reviews and references to previous. reviews see: RooversJ.ComanitaB., Adv. Polym. Sci.142, 179 (1999); MatthewsO.A.ShipwayA.N.StoddartJ.F., Prog. Polym. Sci.23, 1 (1998).
6.
MontaudoG.MontaudoM.S.PuglisiC.SamperiF., J. Polym. Sci., Polym. Chem.34, 439 (1996).
7.
MaloneyD.R.HuntK.H.LloydP.M.MuirA.V.G.RichardsS.N.DerrickP.J.HaddletonD.M., J. Chem. Soc., Chem. Commun.561 (1995).
