Strong Paramagnetism Research Articles

NHC‐Stabilized Parent Phosphinidene Adducts of Metal(II) Hexamethyldisilazanides of Manganese – Cobalt and Their Lability in Solution

AbstractThe behavior of the N‐heterocyclic carbene (NHC) stabilized ‘parent’ phosphinidene [(sIDipp)PH] (Dipp=2,6‐di‐isopropylphenyl) towards 3d‐metal(II) hexamethyldisilazanides is described. This leads to formation of the three‐coordinated phosphinidene adducts [M{PH(sIDipp)}{N(SiMe3)2}2] (M=Mn−Co), as evidenced by X‐Ray diffraction analysis. In solution, all compounds exhibit strong paramagnetism that limited NMR spectroscopic examinations to cobalt. Here it shows that the system is coordinatively highly fluxional, which is mitigtated upon cooling. At low temperatures, small amounts of free phosphinidene becomes further evident by 31P NMR spectroscopy that implicates in part ligand coordination competes with [M{N(SiMe3)2}2] dimerisation and an overall weak binding of the phosphinidene ligand. The rapid chemical exchange is evidenced in the presence of an excess of phosphinidene or a phosphine (PCy3), whereas diethyl ether proved as a stronger donor ligand.

Structure and Magnetism of Few-Layer Nanographene Clusters in Carbon Microspheres

The solid-phase pyrolysis method was used to synthesize carbon microspheres, consisting of clusters of few-layer nanographene and amorphous carbon. Powders of metal-free phthalocyanine and polyethylene served as precursors of the synthesized carbon microspheres. The pyrolysis products of metal-free phthalocyanine samples SPc(700) and SPc(900) contained 4 and 1 atom % nitrogen, respectively, replacing carbon in the graphene lattice in pyrrolic and pyridinic coordination. There are no impurity nitrogen atoms in the products of the pyrolysis of polyethylene. The SPc(700) sample showed strong paramagnetism with a concentration of paramagnetic centers of ∼5 × 1019 spin g–1 and a temperature-independent diamagnetism susceptibility of χDia = −1 × 10–6 emu g–1 Oe–1. In a temperature range of 5–300 K, ferromagnetism was also revealed with a temperature dependence similar to that of ferromagnetic cluster spin glasses, with maximum saturation magnetization, MSFM = 3 × 10–2 emu g–1, and coercive force, Hc = 400 Oe, at Tsg = 25 K. It was shown that the ferromagnetism in the SPc(700) sample is due to π(p)-electrons of zigzag-type edge states as well as nitrogen impurity atoms. The experimental results are interpreted based on the temperature dependence of the spin correlation length. It was revealed that the temperature dependence of the integral of the magnetic resonance absorption intensity closely resembles the temperature behavior of the saturation magnetization of the ferromagnetic component.

GSH-Responsive Drug Delivery System for Active Therapy and Reducing the Side Effects of Bleomycin.

The application of drug delivery system (DDS) has achieved breakthroughs in many aspects, especially in the field of tumor treatment. In this work, polyethylene glycol (PEG)-modified hollow mesoporous manganese dioxide (HMnO2@PEG) nanoparticles were used to load the anti-tumor drug bleomycin (BLM). When the DDS reached the tumor site, HMnO2@PEG was degraded and reduced to Mn2+ by the overexpression of glutathione in the tumor microenvironment, and the drug was released simultaneously. BLM coordinated with Mn2+ in situ, thereby greatly improving the therapeutic activity of BLM. The results of in vivo and in vitro treatment experiments showed that the DDS had excellent responsive therapeutic activation ability. In addition, Mn2+ exhibited strong paramagnetism and was used for T1-weighted magnetic resonance imaging in vivo. Furthermore, this therapeutic mode of responsively releasing drugs and activating in situ effectively attenuated pulmonary fibrosis initiated by BLM. In short, this DDS could help in avoiding the side effects of drugs.

Stereoisomerism in Tetrametallic Propeller‐Like Complexes: A Solid‐State and Solution NMR Study on a Tetragallium(III) Derivative

AbstractTetragallium(III) complex in [Ga4(L4‐Py)2(dpm)6] ⋅ EtOH, with H3L4‐Py=2‐(hydroxymethyl)‐2‐(pyridin‐4‐yl)propane‐1,3‐diol and Hdpm=dipivaloylmethane, was investigated as a diamagnetic analogue of tetrametallic, propeller‐like single‐molecule magnets (SMMs). The chiral molecular structure partitions the six CH2 protons of each tripodal (L4‐Py)3− ligand into two diastereotopic sets. The two signals were clearly detected by 1H NMR spectroscopy in C6D6, proving that Λ and Δ enantiomers interconvert slowly over NMR timescale. Density functional theory calculations provided quantitative agreement with the observed values of chemical shifts and scalar coupling constants across both geminal and long‐range interaction pathways. The solid‐state structure suggests the occurrence of a lower symmetry stereoisomer (27 mol%), which was clearly identified in the NMR spectra. Since high spin Fe3+ forms distinctly more inert complexes than Ga3+, comparable or greater configurational stability is expected for the isostructural FeIII4, FeIII3CrIII, and FeIII3VIII SMMs, which are difficult to investigate by solution NMR because of the strong paramagnetism.

Observations of the effect of strong Pauli paramagnetism on the vortex lattice in superconducting CeCu2Si2

We present the results of a study of the vortex lattice in the heavy fermion superconductor ${\mathrm{CeCu}}_{2}{\mathrm{Si}}_{2}$, using small-angle neutron scattering (SANS). In this material at temperatures well below ${T}_{\mathrm{c}}\ensuremath{\sim}0.6$ K, the value of the upper critical field ${B}_{\mathrm{c}2}\ensuremath{\sim}2.2$ T is strongly limited by the Pauli paramagnetism of the heavy fermions. In this temperature region, our SANS data show an increase in the magnetization of the flux line cores with field, followed by a rapid fall near ${B}_{\mathrm{c}2}$. This behavior is the effect of Pauli paramagnetism and we present a theory-based model, which can be used to describe this effect in a range of materials. The pairing in ${\mathrm{CeCu}}_{2}{\mathrm{Si}}_{2}$ appears to arise from the effect of magnetic fluctuations, but the evidence for a $d$-wave order parameter is rather weak. We find that the vortex lattice structure in ${\mathrm{CeCu}}_{2}{\mathrm{Si}}_{2}$ is close to regular hexagonal. There are no phase transitions to square or rhombic structures; such transitions are expected for $d$-wave superconductors and observed in ${\mathrm{CeCoIn}}_{5}$; however, the temperature dependence of the SANS intensity indicates that both large and small gap values are present, most likely due to multiband $s$-wave superconductivity, rather than a nodal gap structure.

Revealing channel polarization of atomic contacts of ferromagnets and strong paramagnets by shot-noise measurements

We report measurements of the shot noise of atomic contacts of the ferromagnets cobalt and gadolinium and the strong paramagnets palladium, platinum, and iridium. The contacts are fabricated using the mechanically controlled break-junction technique at 4 K. Single-atom contacts of Co and Gd with conductance smaller than the conductance quantum show reduced noise compared to the expectation for the spin-degenerate single-channel case. We discuss by how far this observation gives evidence for spin-polarized transport. Pd, Pt, and Ir reveal noise levels which are above, but close to the threshold to the spin-degenerate single-channel situation. Since for such multivalent metals more than one channel is expected to contribute to the transport, our findings do not exclude spin-polarized transport for these elements. We observe an anticorrelation between the minimum noise and the bulk Stoner parameter of these elements, supporting that spin polarization might be reflected in the shot-noise signal in strong paramagnets.

In situ supported of silver nanoparticles on Thymbra spicata extract coated magnetic nanoparticles under the ultrasonic condition: Its catalytic activity in the synthesis of Propargylamines and their anti-human colorectal properties in the in vitro condition

This work describes an eco-friendly approach for in situ immobilization of Ag nanoparticles on the surface of Fe3O4 nanoparticles, with the help of Thymbra spicata extract and ultrasound irradiations, without using any toxic reducing and capping agents. The combination of Fe3O4 NPs and Ag NPs in one hybrid nanostructure (Fe3O4@T. spicata/Ag NPs) represents a promising strategy for targeted biomedical applications. The structure, morphology, and physicochemical properties were characterized by various analytical techniques such as fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and vibrating sample magnetometer (VSM). Towards the chemical applications of the material, we headed the multicomponent synthesis of diverse propargylamines by A3 coupling in water, which ended up with excellent yields. Due to strong paramagnetism, the catalyst was easily isolable and reused in 8 cycles without any leaching and considerable change in reactivity. DPPH test revealed similar antioxidant potentials for hybrid nanostructure and butylated hydroxytoluene. The hybrid nanostructure inhibited half of the DPPH molecules in the concentration of 139 µg/mL. To survey the anti-human colorectal cancer activities of the hybrid nanostructure, MTT assay was used on common human colorectal cancer cell lines. The hybrid nanostructure had very low cell viability and anti-human colorectal cancer effects dose-dependently against Ramos.2G6.4C10, HCT-8 [HRT-18], and HCT 116 cell lines. The IC50 values of the hybrid nanostructure were 289, 311, and 174 µg/mL against Ramos.2G6.4C10, HCT-8 [HRT-18], and HCT 116 cell lines, respectively. It is thought that the hybrid nanostructure obtained can be used as an anticancer drug for the diagnosis of colorectal cancer in humans after acceptance of the above findings in clinical study trials.

Immobilized Ag NPs on chitosan-biguanidine coated magnetic nanoparticles for synthesis of propargylamines and treatment of human lung cancer

The magnetically isolable nanobiocomposites have significant impact as the modified new generation catalysts in recent days. This has persuaded us to design and synthesis of a novel Ag NPs decorated biguanidine-chitosan (Bigua-CS) dual biomolecular functionalized core-shell type magnetic nanocomposite (Ag/Bigua-CS@Fe3O4). Bigua-CS could be introducing polysaccharide materials as potential coating agent to immobilizing and stabilizing metal nanoparticles. The material was characterized using several advanced techniques like fourier transformed infrared spectroscopy (FT-IR), inductively coupled plasma (ICP), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic mapping, high resolution transmission electron microscopy (HR-TEM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). Towards the chemical applications of the material, we headed the multicomponent synthesis of diverse propargylamines by A3 coupling in water, which ended up with excellent yields. Due to strong paramagnetism, the catalyst was easily isolable and reused in 9cycles without any leaching and considerable change in reactivity. In addition, the catalyst was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC50 value in radical scavenging assay, we extended the bio-application of the catalyst in anticancer study of adenocarcinoma cells of human lungs. The three different cancer cell lines, PC-14, LC-2/ad and HLC-1 were used in this regard. The best result was achieved in the case of PC-14 cell line with strong IC50 values.

In situ decorated Au NPs on pectin-modified Fe3O4 NPs as a novel magnetic nanocomposite (Fe3O4/Pectin/Au) for catalytic reduction of nitroarenes and investigation of its anti-human lung cancer activities

In recent days, the green synthesized nanomagnetic biocomposites have been evolved with tremendous potential as the future catalysts. This has encouraged us to design and synthesis of a novel Au NPs immobilized pectin modified magnetic nanoparticles (Fe3O4/Pectin/Au). It was meticulously characterized using advanced analytical techniques like FT-IR, FESEM, TEM, EDX, XPS, VSM, XRD and ICP-OES. We investigated the chemical applications of the material in the catalytic reduction of nitroarenes using N2H4.H2O as the reducing agent in the EtOH/H2O solvent without any promoters or ligands. Due to strong paramagnetism, the catalyst was easily recovered and reused in 11 cycles without considerable leaching or loss in reactivity. The green protocol involves several advantages like mild conditions, easy workup, high yields, and reusability of the catalyst. Furthermore, the desired nanocomposite was employed in biological studies like anti-oxidant assay by DPPH radical scavenging test. Subsequently, on exhibiting a good IC50 value in the DPPH assay, we extended the bio-application of the Fe3O4/Pectin/Au in the anticancer study of adenocarcinoma cells of human lungs using three cancer cell lines, PC-14, LC-2/ad and HLC-1 and a normal cell line HUVEC. The best result was accomplished in PC-14 cell lines with the lowest IC50 values.

Magnetic susceptibility of QCD matter and its decomposition from the lattice

We determine the magnetic susceptibility of thermal QCD matter by means of first principles lattice simulations using staggered quarks with physical masses. A novel method is employed that only requires simulations at zero background field, thereby circumventing problems related to magnetic flux quantization. After a careful continuum limit extrapolation, diamagnetic behavior (negative susceptibility) is found at low temperatures and strong paramagnetism (positive susceptibility) at high temperatures. We revisit the decomposition of the magnetic susceptibility into spin- and orbital angular momentum- related contributions. The spin term — related to the normalization of the photon lightcone distribution amplitude at zero temperature — is calculated non-perturbatively and extrapolated to the continuum limit. Having access to both the full magnetic susceptibility and the spin term, we calculate the orbital angular momentum contribution for the first time. The results reveal the opposite of what might be expected based on a free fermion picture. We provide a simple parametrization of the temperature- and magnetic field-dependence of the QCD equation of state that can be used in phenomenological studies.

High-pressure synthesis, crystal structure, and magnetic properties of the Shastry-Sutherland-lattice oxides BaLn2ZnO5 (Ln = Pr, Sm, Eu)

BaPr2ZnO5, BaSm2ZnO5, and BaEu2ZnO5 – a series of 4f magnetic insulators comprising the Shastry-Sutherland lattice – were synthesized via a solid-state reaction under high-pressure and high-temperature conditions. The magnetic behaviors are well characterized by the localized 4f electrons of each Ln3+ (= Pr, Sm, Eu) under the influence of the crystal-electric field of the surrounding ions. The magnetic susceptibility and heat capacity measurements of BaPr2ZnO5 (Pr3+; 4f23H4) indicate the splitting of the ground state J-multiplet due to the crystal-electric field. BaSm2ZnO5 (Sm3+; 4f56H5/2) is a strong Van Vleck paramagnet, while BaEu2ZnO5 is non-magnetic due to the 7F0 ground state (Eu3+; 4f67F0). The series of new oxides enriches a group of the Shastry-Sutherland lattice materials and helps to develop a range of two-dimensional quantum materials.

Decoupling of Gd–Cr magnetism and giant magnetocaloric effect in layered honeycomb tellurate GdCrTeO6

We report the decoupling of Gd–Cr magnetism and the resulting giant magnetocaloric effect in honeycomb-lattice tellurate GdCrTeO6. This compound adopts the hexagonal structure with the space group P-3. The susceptibility curve presents a paramagnetic behavior from room temperature to 2 K. Very intriguingly, however, the heat capacity measurement probes a λ-like peak at TN = 10 K, characterizing the long-range antiferromagnetic order. This suggests that the Gd and Cr sublattices are magnetically independent, i.e., the Gd ions are paramagnetic and the strong paramagnetism nearly masks the antiferromagnetic order of Cr ions, which is further evidenced by our ESR data. The maximum magnetic entropy change at 2 K is 41.8 J kg−1 K−1 in a field range of 0–7 T and 30.3 J kg−1 K−1 for 0–3 T, larger than those of most of the Gd oxides reported. The observed giant magnetocaloric effect is due to strong paramagnetism of Gd ions.

Manganese-Enhanced Magnetic Resonance Imaging: Application in Central Nervous System Diseases.

Manganese-enhanced magnetic resonance imaging (MEMRI) relies on the strong paramagnetism of Mn2+. Mn2+ is a calcium ion analog and can enter excitable cells through voltage-gated calcium channels. Mn2+ can be transported along the axons of neurons via microtubule-based fast axonal transport. Based on these properties, MEMRI is used to describe neuroanatomical structures, monitor neural activity, and evaluate axonal transport rates. The application of MEMRI in preclinical animal models of central nervous system (CNS) diseases can provide more information for the study of disease mechanisms. In this article, we provide a brief review of MEMRI use in CNS diseases ranging from neurodegenerative diseases to brain injury and spinal cord injury.

Simultaneous MRI water-fat separation and quantitative susceptibility mapping of carotid artery plaque pre- and post-ultrasmall superparamagnetic iron oxide-uptake.

Imaging carotid artery plaques to identify features of vulnerability typically requires a multicontrast MRI protocol. The identification of regions of inflammation with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles requires separate pre- and postcontrast scans. We propose a method of joint water-fat separation and quantitative susceptibility mapping (QSM) to aid classification of atherosclerotic plaques and offer a positive contrast mechanism in USPIO-imaging. Ten healthy volunteers (3 women and 7 men; aged, 30.7 ± 10.7 years) were imaged at 1.5T to develop an acquisition and postprocessing protocol. Five patients (1 woman and 4 men; mean age, 71 ± 7.5 years) with moderate to severe luminal stenosis were imaged pre- and postadministration of a USPIO contrast agent. We used a multiecho gradient echo acquisition to perform water/fat separation and subsequently QSM. The results were compared with a conventional multicontrast MRI protocol, CT images, and histopathology data. In the volunteer scans, a multiecho gradient echo acquisition with bipolar readout gradients demonstrated to be a reliable acquisition methodology to produce high-quality susceptibility maps in conjunction with the proposed postprocessing methodology. In the patient study, water/fat separation provided a tool to identify lipid-rich necrotic cores and QSM provided a qualitative and quantitative evaluation of plaque features and positive contrast when evaluating USPIO uptake. Plaque calcification could be identified by strong diamagnetism (-1.27 ± 0.71 ppm), while USPIO uptake demonstrated a strong paramagnetism (1.32 ± 0.61 ppm). QSM was able to identify multiple plaque features in a single acquisition, providing positive contrast for plaques demonstrating USPIO uptake and negative contrast for calcification.

Tuning the magnetic anisotropy energy of atomic wires

In this article we present the fabrication of freestanding thin-film nanobridges of Ir. We perform magnetoconductance (MC) measurements of atomic contacts and monoatomic chains of Ir, realized by the mechanically controlled break-junction method. We observe continuous changes of the MC on the field scale of several tesla, as observed earlier for atomic-size contacts of two other strong paramagnets, Pd and Pt. The amplitude and the shape of the MC depend on the orientation of the magnetic field as well as on subtle details of the atomic arrangement, as confirmed by stretching studies of the contacts. Both positive dominant MC and negative dominant MC occur and are attributed to collinear or noncollinear alignment of the magnetic moments of the electrodes, respectively. By careful manipulation of the chain geometry we are able to study the transition between these two cases, which is hallmarked by a complex MC behavior. For special arrangements the MC almost vanishes. Our findings are in agreement with recent calculations of the geometry dependence of the magnetic anisotropy energy and open a route to tailor the MC behavior as required for particular applications.

Preparation of water-soluble amorphous erbium borate (ErBO3.3H2O) nanoparticles with positive charge

We report a simple one-step protocol for the preparation of nearly monodisperse and highly water-soluble erbium borate nanoparticles through a co-precipitation method. Erbium ions were precipitated by boric acid/sodium hydroxide buffer with a pH of 9.2 in the presence of polyethylene glycol (2000 gmol−1) (PEG). As a result of the X-ray diffraction analysis, it was determined that the products that were precipitated in the medium with/without PEG were amorphous and the calcined product has an appropriate pattern for the vaterite-type ErBO3 crystal structure. Infrared spectrophotometer and thermal gravimetric analysis revealed the chemical formulation of the ErBO3.3H2O compound. It was found that partially spherical nanoparticles have a size of 15 ± 6 nm according to TEM images. The average particle size was also measured in the water using dynamic light scattering method. The particles size is equal to about 100 nm in water and the zeta potential of particles is + 41 mV, which indicates a highly stable colloidal solution. Besides ErBO3.3H2O nanoparticles showed strong paramagnetism, their Bohr magnetron number was found as 9.48. Thus, these nanoparticles have promising properties for biomedical applications, such as cell targeting, drug delivery, and bioimaging.

Intense light scattering by cooperative relaxation of magnetically-aligned organic crystal particles

Previous studies of biologically mineralized crystals made of iron have focused on their magnetic properties, including strong magnetism and para magnetism, and many useful applications have been developed. Some studies have focused on organic crystals or crystals with diamagnetism, and have proven that utilizing magnetic fields of more than 0.5 T results in a magnetically-induced rotation of the crystal particles. The rotation of an appropriately shaped crystal particle can be detected by light reflection. In the present study, we demonstrate a newly discovered phenomenon associated with organic crystal particles in water. A cooperative light reflection phenomenon is observed when the micro-particles floating in water are rotated together. The organic crystal particles, made of guanine in a platelet-like shape of micrometer length, cause a cooperative light reflection pattern during magnetic field sweeps of up to 5 Tesla (T). This cooperative light reflection appears as peaks in the intensity of the reflected light. When the magnetic field is increased at a sweep rate of +1 T per minute, two peaks are detected at 0.5 T and at ∼1.5 T. After reaching 5 T, the reflected light is continuously measured until the magnetic field returns to 0 T. In over 10 minutes of magnetic field exposure, a final peak is frequently detected as a maximum intensity peak. The intensity enhancement is twice the randomly reflected light intensity in this maximum case. A model explaining this magnetically-controlled optical phenomenon in a group of platelet-like guanine particles is proposed.

Study on Synthesis of Acid-Washed Illite Supported Fe3O4 Nanometer Catalyst and Baeyer–Villiger Oxidation Reaction of Cyclohexanone

Baeyer–Villiger oxidation allows for effective control of the stereochemical structure of the product, which is a significant feature for functional group conversion and ring expansion in organic synthesis. In this study, Fe3O4 nanoparticles were loaded on acid-washed porous illite silicon slag (I-SR) using an in situ hydrothermal method to obtain the magnetic composite Fe3O4@I-SR. This composite was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N2 adsorption–desorption isotherm measurements, vibrating sample magnetometer analysis, etc. The results indicated that the Fe3O4 nanoparticles had a face-centered cubic lattice geometry with an average size of about 10 nm; the nanoparticles were uniformly dispersed on the surface of the carrier (I-SR) and exhibited strong paramagnetism. Fe3O4@I-SR composite was found to be a promising and efficient catalyst with high activity (> 99% cyclohexanone conversion and > 99% e-caprolactone selectivity) for the Baeyer–Villiger of cyclohexanone to e-caprolactone. The catalyst could be easily separated from the reaction mixture and reused many times. Thus, Fe3O4@I-SR is an attractive multiphase catalyst that is easy to handle and recycle under environmentally friendly reaction conditions.

Ultra-small nanocluster mediated synthesis of Nd3+-doped core-shell nanocrystals with emission in the second near-infrared window for multimodal imaging of tumor vasculature

In-vivo intravital short wavelength infrared (SWIR, 1000–2300 nm) fluorescence imaging has attracted considerable attention in the imaging of tumor vasculature due to its low background, high sensitivity, and deep penetration. It can noninvasively provide dynamic feedback on the tumorigenesis, growth, necrosis and metastasis. Herein, monodisperse Nd3+-doped core-shell downconversion luminescent nanocrystals with strong emission in the second near-infrared (NIR II) window, strong temperature-dependent paramagnetism and fast attenuation to X-rays were prepared from ultra-small nanoclusters. The use of nanoclusters resulted in very uniform bright nanocrystals with a relative quantum yield comparable to the standard dye IR-26. These bright NIR nanocrystals were modified with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] to endow with excellent water-solubility, biocompatibility and a blood circulation half-life of 5.9 h. They were then successfully used to demonstrate the variation of tumor vasculature with tumor progression from tumorigenesis, growth, to necrosis in the subcutaneous breast tumor through the NIR II fluorescence imaging. They were also used as contrast agent of magnetic resonance imaging (MRI) and X-ray computed tomography (CT) imaging of tumor to provide complementary anatomic structure. Their great potential in NIR II imaging of tumor was further demonstrated with an orthotopic breast tumor. Their in-vivo biosafety was also investigated by hemanalysis and histological analyses.

Novel Synthesis of Slightly Fluorinated Graphene Quantum Dots with Luminescent and Paramagnetic Properties through Thermal Cutting of Fluorinated Graphene.

A novel approach has been developed to synthesize slightly fluorinated graphene quantum dots (GQDs-F) through thermal cutting of highly fluorinated graphene. The fluorinated graphene with substantial structure defects is fragile and is readily attacked. The direct evaporation of abundant CFn (n = 2, 3) groups near structure defects lead to the loss of adjacent skelton C atoms, and the fluorinated graphene can be thermally cut into GQDs-F with a relatively uniform nanosize in pyrolysis at 810 K. The GQDs-F with a low F/C atomic ratio of ca. 0.03 exhibit excitation wavelength-dependent properties with multicolor photoluminescence (PL) from blue to green. At the same time, F adatoms that are most likely located at the edges of GQDs-F have a high efficiency of introducing paramagnetic centres, and GQDs-F show a strong paramagnetism because of sp3-type defects and magnetic zigzag edges. The graphene quantum dots with such multimodal capabilities should have great applied value in material science.