# Local NMR Relaxation of Dendrimers in the Presence of Hydrodynamic Interactions

## TL;DR

This paper investigates how hydrodynamic interactions influence the NMR relaxation behavior of dendrimer segments, revealing that such interactions significantly enhance inner segments' mobility and alter spectral density profiles.

## Contribution

It introduces a Zimm framework analysis of dendrimer relaxation, emphasizing the importance of segment correlations and hydrodynamic effects on NMR relaxation functions.

## Key findings

- Hydrodynamic interactions increase inner segments' reorientation dynamics.
- Spectral density maximum shifts to higher frequencies with hydrodynamic effects.
- Segment correlations are crucial for accurate relaxation modeling.

## Abstract

We study the role of hydrodynamic interactions for the relaxation of segments' orientations in dendrimers. The dynamics is considered in the Zimm framework. It is shown that inclusion of correlations between segments' orientations plays a major role for the segments' mobility, that reveals itself in the NMR relaxation functions. The enhancement of the reorientation dynamics of segments due to the hydrodynamic interactions is more significant for the inner segments. This effect is clearly pronounced in the reduced spectral density $\omega J(\omega)$, whose maximum shifts to higher frequencies when the hydrodynamic interactions are taken into account.