# US 11,273,431 B2 · Biologically applicable water-soluble heterogeneous catalysts for para-hydrogen induced polarization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,273,431 B2 - Document ID: US11273431B2 - Status: Granted - Kind: B2 - Application number: 15/799,498 - Filed: 2017-10-31 - Published: 2018-05-03 - Granted: 2022-03-15 - Earliest claimed: 2016-11-01 - Assignees: The Regents of the University of California; Cedars-Sinai Medical Center - Applicants: The Regents of the University of California; Cedars-Sinai Medical Center - Inventors: Louis Bouchard; Shawn Wagner; Stefan Gloeggler - Web page: https://patentgrep.com/patent/US11273431B2 ## CPC - B01J 31/1625: {immobilised by covalent linkages, i.e. pendant complexes with optional linking groups} - A61K 49/10: Organic compounds - B01J 23/42: Platinum - B01J 29/0308: {Mesoporous materials not having base exchange properties, e.g. Si-MCM-41} - B01J 29/084: {Y-type faujasite} - B01J 29/40: of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively - B01J 29/44: Noble metals - B01J 29/7007: {Zeolite Beta} - B01J 29/80: Mixtures of different zeolites - B01J 29/89: Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium {(B01J29/005 takes precedence)} - B01J 35/397: {Egg shell like} - B01J 35/45: Nanoparticles - B01J 35/51: Spheres - B01J 35/615: {100-500 m2/g} - B01J 35/633: {less than 0.5 ml/g} - B01J 35/647: {2-50 nm} - B01J 37/0018: {Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)} - B01J 37/0221: {of particles} - B01J 37/031: {Precipitation} - B01J 37/16: Reducing - C07C 67/303: by hydrogenation of unsaturated carbon-to-carbon bonds - B01J 2229/186: not in framework positions - B01J 2231/645: of C=C or C-C triple bonds - B01J 2235/00: Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties - B01J 2235/05: Nuclear magnetic resonance [NMR] - B01J 2235/30: Scanning electron microscopy; Transmission electron microscopy - B01J 2531/0222: Metal clusters, i.e. complexes comprising 3 to about 1000 metal atoms with metal-metal bonds to provide one or more all-metal (M)n rings, e.g. Rh4(CO)12 - B01J 2531/0275: derived from amino acids - B01J 2531/828: Platinum - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract A heterogeneous catalyst composition for para-hydrogen induced polarization includes ligand-capped nanoparticles dispersed in water. The ligand-capped nanoparticles include metal nanoparticles that are surface functionalized with organic ligands, a molecular weight of the organic ligands is no greater than 300 g/mol, and the organic ligands each includes multiple binding moieties as coordinates sites for binding to a nanoparticle surface. ## Claims ### Claim 1 A heterogeneous catalyst composition for para-hydrogen induced polarization, comprising ligand-capped nanoparticles dispersed in water, wherein the ligand-capped nanoparticles include metal nanoparticles consisting of a platinum group metal that are surface functionalized with an organic ligand, a molecular weight of the organic ligands is no greater than 250 g/mol, and the organic ligands each includes multiple binding moieties as coordination sites for binding to a nanoparticle surface, wherein the organic ligands each includes a sulfhydryl group and an amino group as the binding moieties, and further includes at least one hydrophilic moiety, wherein the platinum group metal is rhodium. ### Claim 2 (depends on 1) The composition of claim 1, wherein a surface coverage of the metal nanoparticles consisting of a platinum group metal by the organic ligands is at least 4.2 ligands per nm2. ### Claim 3 (depends on 1) The composition of claim 1, wherein a surface coverage of the metal nanoparticles consisting of a platinum group metal by the organic ligands is at least 8 ligands per nm2. ### Claim 4 (depends on 1) The composition of claim 1, wherein the molecular weight of the organic ligands is no greater than 200 g/mol. ### Claim 5 (depends on 1) The composition of claim 1, wherein the organic ligands are amino acids. ### Claim 6 (depends on 1) The composition of claim 1, wherein the organic ligands are cysteine, acetylcysteine, or a combination thereof. ### Claim 7 (depends on 1) The composition of claim 1, wherein the hydrophilic moiety is a carboxyl group. ### Claim 8 (depends on 1) The composition of claim 1, wherein the metal nanoparticles consisting of a platinum group metal have an average size in a range of 0.5 nm to 10 nm. ### Claim 9 (depends on 1) The composition of claim 1, wherein a concentration of the ligand-capped nanoparticles is in a range of 1 mg/mL to 20 mg/mL. ### Claim 10 (depends on 1) A method for medical imaging, comprising: hydrogenating an organic substrate, in the presence of the heterogeneous catalyst composition of claim 1, by flowing or pressurizing para-hydrogen gas to yield a polarized organic substrate; and removing the ligand-capped nanoparticles from the polarized organic substrate. ### Claim 11 (depends on 10) The method of claim 10, wherein the ligand-capped nanoparticles are cysteine-capped nanoparticles. ### Claim 12 (depends on 1) The composition of claim 1, wherein the organic ligands are cysteine, acetylcysteine, or a combination thereof. ### Claim 13 (depends on 1) The composition of claim 1, wherein the ligand-capped nanoparticles yield average proton polarizations greater than or equal to 0.65% in water. ### Claim 14 A method for synthesis of ligand-capped nanoparticles, comprising: combining a platinum group metal-containing precursor and organic ligands in a solvent; and reducing the platinum group metal-containing precursor in the presence of a reducing agent, thereby forming the ligand-capped nanoparticles, wherein the ligand-capped nanoparticles include metal nanoparticles consisting of a platinum group metal that are surface functionalized with the organic ligand, wherein a molecular weight of the organic ligands is no greater than 250 g/mol, and the organic ligands each includes multiple binding moieties as coordination sites for binding to a nanoparticle surface, wherein the organic ligands each includes a sulfhydryl group and an amino group as the binding moieties, and further includes at least one hydrophilic moiety, wherein the platinum group metal is selected from the group consisting of rhodium. ### Claim 15 (depends on 14) The method of claim 14, wherein the metal-containing precursor is a rhodium metal-containing precursor, and the organic ligands are amino acids. ### Claim 16 (depends on 14) The method of claim 14, wherein the organic ligands are cysteine. ### Claim 17 (depends on 14) The method of claim 14, wherein a molar ratio of the platinum group metal-containing precursor to the organic ligands is in a range of 1:2 to 2:1.