Crystal engineering using functionalized adamantane

Journal of Applied Spectroscopy

We have used the density functional method to model the atomic and electronic structure of diamond nanocrystals passivated by hydrogen atoms and either not containing defects or containing a single [NV]-center. We have shown that in all cases, after relaxation the nanocrystals are formed as diamond-like structures.

The journal of physical chemistry. A, 2018

The rational control of the electronic and optical properties of small functionalized diamond-like molecules, the diamondoids, is the focus of this work. Specifically, we investigate the single- and double- functionalization of the lower diamondoids, adamantane, diamantane, and triamantane with -NH and -SH groups and extend the study to N-heterocyclic carbene (NHC) functionalization. On the basis of electronic structure calculations, we predict a significant change in the optical properties of these functionalized diamondoids. Our computations reveal that -NH functionalized diamondoids show UV photoluminescence similar to ideal diamondoids while -SH substituted diamondoids hinder the UV photoluminescence due to the labile nature of the S-H bond in the first excited state. This study also unveils that the UV photoluminescence nature of -NH diamondoids is quenched upon additional functionalization with the -SH group. The double-functionalized derivative can, thus, serve as a sensitive...

Encyclopedia of Nanotechnology, 2009

Diamondoids have been of great interest in recent years due to their role in nanotechnology, drug-delivery and medicine. Due to their six or more linking groups, they have found major applications as templates and as molecular building blocks in nanotechnology, polymers synthesis, drug delivery, drug targeting, DNA-directed assembly, DNA-amino acid nanostructure formation, and in host-guest chemistry. In this paper, the molecular nature of diamondoids, their molecular specificities, their intermolecular interactions and their opto-electronic properties are introduced. These will help in the understanding of the structure-property relations and self-assembly of diamondoids, which is essential for designing functional molecular gears for micro-electro-mechanical systems (MEMS) and sensitive bionanosensors, and for developing new nanodrugs, just to name a few.

2016

Unusual optoelectronic properties of diamondoids produce some discrepancies between experiments and the outstanding many-body calculation outputs. Therefore, many theoretical efforts are attracted to resolve these inconsistencies. Here first, by combining time-dependent density functional theory (TD-DFT) and Franck-Condon (FC) approximation, the effect of electron-phonon (e-ph) interaction on the optical gap (OG) of the smallest diamondoids and one of its derivatives is studied. Then, the surface effects on the e-ph coupling and the optical properties of these structures in a comparative manner are considered. We show that the collective motion of carbons modifies the previous OG of adamantane predicted by TD-DFT technique. The introduction of this effect can also fully explain the overestimated gap predicted by the diffusion quantum Monte-Carlo (DMC) method. In addition, we show that the chemistry of the surface is another noticeable effect that can influence the OG renormalization...

2015

The electronic, structural and vibrational properties of gallium phosphide diamondoids and nanocrystals were investigated using density functional theory at PBE/6-31(d) level, which included polarization functions. The energy gap obeyed the quantum confinement size effect with shape fluctuations. The gap converged towards its bulk limit at 2.26 eV. The Ga-P bond lengths of higher diamond‐ oids were found to be distributed around the bulk experi‐ mental value at 2.36 Angstrom. Tetrahedral angles were found around the ideal bulk zincblende value at 109.47, degrees while dihedral angles were distributed around the ideal bulk zincblende values at ±60 and ±180 degree. These findings illustrate that diamondoids are a good represen‐ tative of bulk structure. An analysis of vibrational modes, in terms of reduced masses, force constants and IR intensi‐ ty, was then performed. The size-related change of certain vibrational frequencies of GaP diamondoids was compared with the experimental bulk...

Diamondoid Molecules, 2012

A SHORT DESCRIPTION OF THIS BOOK: Diamondoids (a.k.a. Nanodiamonds) are cage-like, ultra stable, saturated ringed hydrocarbons, which have a diamond-like structure consisting of a number of six-member carbon rings fused together. Adamantane is the cage compound prototype and the simplest diamondoid molecule. Diamondoids Molecules aims to present these fascinating substances in a novel fashion. The more intriguing facets of diamondoid molecules are comprehensively exposed and discussed, bringing state-of-the-art information to the reader, along with the history, fundamentals and perspectives of diamondoid science and technology. This groundbreaking book, especially devoted to diamondoid molecules, is of critical importance to the global techno-scientific community, and will be of great interest in many research fields such as chemistry, physics, material science, geology, and biological sciences. Moreover, it will attract readers from industrial, government and environmental agencies as well as scholars.

Topics in Applied Physics, Springer, 2007

Preface MolecularBuildingBlocksforNanotechnology:FromDiamondoidstoNanoscale Materials and Applications is a result of the research and educational activities of a group of outstanding scientists worldwide who have authored the chapters of this book dealing with the behavior of nanoscale building blocks. It contains a variety of subjects covering computational, dry and wet nanotechnology. The state-of-the-art subject matters are presented in this book which can provide the reader with the latest developments on the ongoing bottom-up nanoscience and nanotechnology research. The editors would like to thank all the chapter authors whose scholarly contributions have made publication of this book possible. We would like to thank Springer for agreeing to publish this book as part of its Topics in Applied Physics Series. We also acknowledge the support of the U.S. Army Research Office under contract W911NF-04-1-0383. G. Ali Mansoori Thomas F. George Guoping Zhang Lahsen Assoufid 2007

Diamondoid Molecules with Applications in Biomedicine, Materials Science, Nanotechnology & Petroleum Science, 2012

INTRODUCTION Diamondoid molecules are cage-like, ultra stable and saturated hydrocar-bons. The basic repetitive unit of the diamondoids is a ten carbon tetracy-clic cage system called “adamantane” (Fig. 1.1). They are called “diamondoid” because they have at least one adamantane unit and their carbon–carbon framework is completely or largely superimposable on the diamond lattice (Balaban and Schleyer, 1978; Mansoori, 2007). The diamond lattices structure was first determined in 1913 by Bragg and Bragg using X-ray diffraction analysis (Bragg and Brag, 1913). Diamondoids show unique properties due to their exceptional atomic arrangements. Adamantane consists of cyclohexane rings in “chair” conformation. The name adamantane is derived from the Greek language word for diamond since its chemical structure is like the three-dimensional diamond subunit as it is shown in Fig. 1.2.

Proceedings of the International Congress of Nanotechnology 2005 , 2005

Physical and chemical properties of diamondoids, which are organic compounds with unique structures and properties, are investigated as molecular building blocks (MBBs) for nanotechnology. Some methods and concepts in their role as MBBs in the formation of nanostructures including various aspects of self-assembly are introduced. Those include self-assembly using a solid surface, immobilization techniques for molecules on a solid support, DNA-directed self-assembly, self-assembly in liquid medium, and a host-guest chemistry approach. The applications of diamondoids in host-guest chemistry to construct molecular receptors by self-assembly process are presented. A combined experimental and theoretical effort to investigate the complicated structure-property relation of diamond-like and self-assembling organic nanostructures at the nanoscale level is presented. It is concluded that diamondoids are one of the best candidates for MBBs in molecular nanotechnology to design nanostructures with predetermined physicochemical properties. 2

C

One type of two-dimensional diamonds that are derived from [111] direction, so-called diamane, has been previously shown to be stabilized by N-substitution, where the passivation of dangling bonds is no longer needed. In the present work, we theoretically demonstrated that another type of two-dimensional diamonds derived from [110] direction exhibiting a washboard conformation can also be stabilized by N-substitution. Three structural models of washboard-like carbon nitrides with compositions of C6N2, C5N3, and C4N4 are studied together with the fully hydrogenated washboard-like diamane (C8H4). The result shows that the band gap of this type structure is only open the dangling bonds that are entirely diminished through N-substitution. By increasing the N content, the C11 and C22 are softer and the C33 is stiffer where their bulk modulus are in the same order, which is approximately 550 GPa. When comparing with the hydrogenated phase, the N-substituted phases have higher elastic cons...