TY - JOUR

T1 - NMR Relaxation of Functionalized Dendrimers

AU - Sheveleva, Nadezhda N.

AU - Dolgushev, Maxim

AU - Lähderanta, Erkki

AU - Markelov, Denis A.

PY - 2019/12/24

Y1 - 2019/12/24

N2 - Functionalized dendrimers are a novel type of dendritic macromolecules that contain functionalized groups that do not take part in the dendrimer's synthetic cycle. Focusing on the local dynamics of the functionalized dendrimers, we study NMR relaxation by considering the spin-lattice relaxation rate 1/T1(ω) of the 1H and 13C nuclei and the corresponding spectral density. The macromolecules are modeled in the framework that accounts for the local bending rigidity, which is of paramount importance for the NMR relaxation of dendritic structures. We show that the behavior of the NMR relaxation of the functionalized dendrimers is qualitatively different from that of the standard dendrimers manifested through an additional maximum in ω/T1(ω). The new theoretical picture has allowed us to analyze recent atomistic molecular dynamics simulations of carbosilane dendrimer melts and to elucidate the differences in the high-frequency behavior of their spin-lattice relaxation rates from the predictions of the standard dendrimer model.

AB - Functionalized dendrimers are a novel type of dendritic macromolecules that contain functionalized groups that do not take part in the dendrimer's synthetic cycle. Focusing on the local dynamics of the functionalized dendrimers, we study NMR relaxation by considering the spin-lattice relaxation rate 1/T1(ω) of the 1H and 13C nuclei and the corresponding spectral density. The macromolecules are modeled in the framework that accounts for the local bending rigidity, which is of paramount importance for the NMR relaxation of dendritic structures. We show that the behavior of the NMR relaxation of the functionalized dendrimers is qualitatively different from that of the standard dendrimers manifested through an additional maximum in ω/T1(ω). The new theoretical picture has allowed us to analyze recent atomistic molecular dynamics simulations of carbosilane dendrimer melts and to elucidate the differences in the high-frequency behavior of their spin-lattice relaxation rates from the predictions of the standard dendrimer model.

KW - macromolecules

KW - molecular dynamics

KW - nuclear magnetic resonance

KW - Polymethyl methacrylates

KW - Spectral density

KW - Spin dynamics

KW - Spin-Lattice Relaxation

UR - http://www.scopus.com/inward/record.url?scp=85076631422&partnerID=8YFLogxK

U2 - 10.1021/acs.macromol.9b01427

DO - 10.1021/acs.macromol.9b01427

M3 - Article

AN - SCOPUS:85076631422

VL - 52

SP - 9766

EP - 9772

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 24

ER -