Determination of the Local Crystal-Chemical Features of Complex Chalcogenides by Copper, Antimony, and Arsenic NQR

Gainov, R.R.; Dooglav, A.V.; Penkov, I.N.; Orlova, A.Yu.; Evlampiev, I.A.; Mozgova, N.N.; Khasanov, R.R.

doi:10.5772/46939

Cited by 1 publication

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References 20 publications

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“…Beyond characterizing QN spin systems, NQR spectroscopy has proven its scientific versatility in several applications and studies as, for example, research on molecular structure [66,67], superconductors [68], semiconductors [69], and phase transitions [70,71], as well as quantum computing [72] and the authentication of medicines [73].…”

Section: A Nqr Spectroscopymentioning

confidence: 99%

Tuning Nuclear Quadrupole Resonance: A Novel Approach for the Design of Frequency-Selective MRI Contrast Agents

et al. 2018

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The interaction between water protons and suitable quadrupolar nuclei (QN) can lead to quadrupole relaxation enhancement (QRE) of proton spins, provided the resonance condition between both spin transitions is fulfilled. This effect could be utilized as a frequency selective mechanism in novel, responsive T 1 shortening contrast agents (CAs) for magnetic resonance imaging (MRI). In particular, the proposed contrast mechanism depends on the applied external flux density-a property that can be exploited by special field-cycling MRI scanners. For the design of efficient CA molecules, exhibiting narrow and pronounced peaks in the proton T 1 relaxation dispersion, the nuclear quadrupole resonance (NQR) properties, as well as the spin dynamics of the system QN-1 H, have to be well understood and characterized for the compounds in question. In particular, the energy-level structure of the QN is a central determinant for the static flux densities at which the contrast enhancement appears. The energy levels depend both on the QN and the electronic environment, i.e., the chemical bonding structure in the CA molecule. In this work, the NQR properties of a family of promising organometallic compounds containing 209 Bi as QN have been characterized. Important factors like temperature, chemical structure, and chemical environment have been considered by NQR spectroscopy and ab initio quantum chemistry calculations. The investigated Bi-aryl compounds turned out to fulfill several crucial requirements: NQR transition frequency range applicable to clinical 1.5-and 3 T MRI systems, low temperature dependency, low toxicity, and tunability in frequency by chemical modification.

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