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We investigate the diffusion of cosmic rays into molecular cloud complexes.Using the cosmic-ray diffusion formalism of Protheroe, et al. (2008), weexamine how cosmic rays diffuse into clouds exhibiting different densitystructures, including a smoothed step-function, as well as Gaussian andinverse-$r$ density distributions, which are well known to trace the structureof star-forming regions. These density distributions were modelled as anapproximation to the Galactic centre cloud G0.216+0.016, a recently-discoveredmassive dust clump that exhibits limited signs of massive star formation andthus may be the best region in the Galaxy to observe synchrotron emission fromsecondary electrons and positrons. Examination of the resulting synchrotronemission, produced by the interaction of cosmic ray protons interacting withambient molecular matter producing secondary electrons and positrons revealsthat, due to projection effects, limb-brightened morphology results in allcases. However, we find that the Gaussian and inverse-$r$ density distributionsshow much broader flux density distributions than step-function distributions.Significantly, some of the compact (compared to the $2.2''$ resolution, 5.3 GHzJVLA observations) sources show non-thermal emission, which may potentially beexplained by the density structure and the lack of diffusion of cosmic raysinto the cloud. We find that we can match the 5.3 and 20 GHz flux densities ofthe non-thermal source JVLA~1 and 6 from Rodr\'{\i}guez & Zapata (2014) with alocal cosmic ray flux density, a diffusion coefficient suppression factor of$\chi=0.1-0.01$ for a coefficient of $3\times10^{27}$ cm$^2$ s$^{-1}$, and amagnetic field strength of 470 $\mu$G.

Prospects for Detection of Synchrotron Emission from Secondary Electrons and Positrons in Starless Cores: Application to G0.216+0.016