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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Exploiting the Marcus inverted region for first-row transition metal–based photoredox catalysis

Second- and third-row transition metal complexes are widely employed in photocatalysis, whereas earth-abundant first-row transition metals have found only limited use because of the prohibitively fast decay of their excited states. Here we report an unforeseen reactivity mode for productive photocatalysis that uses cobalt polypyridyl complexes as photocatalysts by exploiting Marcus inverted region behavior that couples increases in excited-state energies with increased excited-state lifetimes. These cobalt (III) complexes can engage in bimolecular reactivity by virtue of their strong redox potentials and sufficiently long excited-state lifetimes, catalyzing oxidative C(sp 2 )–N coupling of aryl amides with challenging sterically hindered aryl boronic acids. More generally, the results imply that chromophores can be designed to increase excited-state lifetimes while simultaneously increasing excited-state energies, providing a pathway for the use of relatively abundant metals as photoredox catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. C4+ is bonded to four N3- atoms to form corner-sharing CN4 tetrahedra. There is three shorter (1.46 Å) and one longer (1.47 Å) C–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms. In the second N3- site, N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C2N by Materials Project

C2N crystallizes in the cubic Pa-3 space group. The structure is zero-dimensional and consists of twenty-four hydrogen cyanide molecules and twenty-four methane molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CN by Materials Project

CN is alpha carbon monoxide-like structured and crystallizes in the orthorhombic Pbca space group. The structure is zero-dimensional and consists of eight hydrogen cyanide molecules. C3+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.17 Å. N3- is bonded in a single-bond geometry to one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the cubic I-43d space group. The structure is three-dimensional. C4+ is bonded to four equivalent N3- atoms to form corner-sharing CN4 tetrahedra. All C–N bond lengths are 1.47 Å. N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 is Hausmannite structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. there are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded to four equivalent N3- atoms to form corner-sharing CN4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. All C–N bond lengths are 1.54 Å. In the second C4+ site, C4+ is bonded to six equivalent N3- atoms to form CN6 octahedra that share corners with six equivalent CN4 tetrahedra and edges with six equivalent CN6 octahedra. All C–N bond lengths are 1.66 Å. N3- is bonded in a distorted rectangular see-saw-like geometry to four C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the hexagonal P-6m2 space group. The structure is two-dimensional and consists of two C3N4 sheets oriented in the (0, 0, 1) direction. C4+ is bonded in a trigonal planar geometry to three N3- atoms. There is two shorter (1.33 Å) and one longer (1.46 Å) C–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms. In the second N3- site, N3- is bonded in a bent 120 degrees geometry to two equivalent C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three C3N4 sheets oriented in the (0, 0, 1) direction. C4+ is bonded in a trigonal planar geometry to three N3- atoms. There is two shorter (1.33 Å) and one longer (1.46 Å) C–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a bent 120 degrees geometry to two equivalent C4+ atoms. In the second N3- site, N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the cubic P-43m space group. The structure is three-dimensional. C4+ is bonded to four equivalent N3- atoms to form corner-sharing CN4 tetrahedra. All C–N bond lengths are 1.49 Å. N3- is bonded in a trigonal non-coplanar geometry to three equivalent C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C5N4 by Materials Project

C(CN)4 is Iron carbide-derived structured and crystallizes in the trigonal R3c space group. The structure is zero-dimensional and consists of twenty-four hydrogen cyanide molecules and six methane molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the trigonal P31c space group. The structure is three-dimensional. there are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded to four N3- atoms to form corner-sharing CN4 tetrahedra. There are a spread of C–N bond distances ranging from 1.44–1.49 Å. In the second C4+ site, C4+ is bonded to four N3- atoms to form corner-sharing CN4 tetrahedra. All C–N bond lengths are 1.46 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms. In the second N3- site, N3- is bonded in a trigonal non-coplanar geometry to three equivalent C4+ atoms. In the third N3- site, N3- is bonded in a trigonal planar geometry to three C4+ atoms. In the fourth N3- site, N3- is bonded in a trigonal planar geometry to three C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the trigonal P3_1 space group. The structure is two-dimensional and consists of three C3N4 sheets oriented in the (0, 0, 1) direction. there are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of C–N bond distances ranging from 1.32–1.44 Å. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three N3- atoms. There is two shorter (1.34 Å) and one longer (1.45 Å) C–N bond length. In the third C4+ site, C4+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of C–N bond distances ranging from 1.32–1.44 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. In the second N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. In the third N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. In the fourth N3- site, N3- is bonded in a trigonal planar geometry to three C4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CN2 by Materials Project

CN2 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. C4+ is bonded to four equivalent N2- atoms to form corner-sharing CN4 tetrahedra. All C–N bond lengths are 1.49 Å. N2- is bonded in a distorted trigonal planar geometry to two equivalent C4+ and one N2- atom. The N–N bond length is 1.34 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N is alpha-like structured and crystallizes in the cubic P2_13 space group. The structure is zero-dimensional and consists of four trimethylamine molecules. C1+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.39 Å. N3- is bonded in a trigonal planar geometry to three equivalent C1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N is alpha Rhenium trioxide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. C1+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.66 Å. N3- is bonded to six equivalent C1+ atoms to form corner-sharing NC6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N crystallizes in the orthorhombic Cmmm space group. The structure is two-dimensional and consists of two C3N sheets oriented in the (0, 1, 0) direction. there are two inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a linear geometry to two equivalent C1+ atoms. Both C–C bond lengths are 1.31 Å. In the second C1+ site, C1+ is bonded in a distorted L-shaped geometry to one C1+ and two equivalent N3- atoms. Both C–N bond lengths are 1.59 Å. N3- is bonded in a square co-planar geometry to four equivalent C1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N crystallizes in the hexagonal P6_3/mcm space group. The structure is one-dimensional and consists of one C3N ribbon oriented in the (0, 0, 1) direction. C1+ is bonded in a bent 120 degrees geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.83 Å. N3- is bonded in a 6-coordinate geometry to six equivalent C1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional and consists of four methane molecules and one C2N framework. In the C2N framework, C1+ is bonded to four equivalent N3- atoms to form a mixture of corner and edge-sharing CN4 tetrahedra. All C–N bond lengths are 2.07 Å. N3- is bonded in a body-centered cubic geometry to eight equivalent C1+ atoms.

36 MATERIALS SCIENCE↗