LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].-
The reaction of donor, Cr(arene)2 (arene = C6Me6 and C6Me3H3), D, with the acceptor TCNQ, A, results in formation of electron-transfer salts of [D].+[A].- composition. Two phases of [Cr(C6Me3H3)2] .+[TCNQ].- have been structurally characterized. The α-phase belongs to the centrosymmetric C2/c space...
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| Format: | Journal article |
| Language: | English |
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1990
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| _version_ | 1826298218928930816 |
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| author | Ohare, D Ward, M Miller, J |
| author_facet | Ohare, D Ward, M Miller, J |
| author_sort | Ohare, D |
| collection | OXFORD |
| description | The reaction of donor, Cr(arene)2 (arene = C6Me6 and C6Me3H3), D, with the acceptor TCNQ, A, results in formation of electron-transfer salts of [D].+[A].- composition. Two phases of [Cr(C6Me3H3)2] .+[TCNQ].- have been structurally characterized. The α-phase belongs to the centrosymmetric C2/c space group [a = 14.014 (4) Å, b = 16.347 (4) Å, c = 22.964 (6) Å, β = 107.44 (2)°, Z = 8, V = 5019 (5) Å3, T = 23°C, R = 0.082] with the solid-state structure consisting of ⋯D.+D.+A22-D .+D.+⋯ linear chains. Each [TCNQ]- in the [TCNQ]22- dimer is planar, and the intradimer separation is 3.47 Å. The anion-anion overlap is unusual as the dihedral angle between the planes normal to the long molecular axes is 31°. The β-phase crystallizes in the P21/c space group [a = 9.588 (5) Å, b = 16.390 (3) Å, c = 8.419 (6) Å, β = 106.84 (6)°, Z = 2, V = 1266 (9) Å3, T = 23°C, R = 0.044] with the solid-state structure consisting of ⋯D.+A.-D.+A.-⋯ linear chains. The magnetic susceptibility of α- [Cr(C6Me6)2] [TCNQ] obeys the Curie-Weiss law with an effective moment, μeff, of 1-77 μB and θ of -0.1 K. This is consistent with the presence of a diamagnetic [TCNQ]22- dimer (v(C≡N) = 2156 m, 2175 s, and 2182 s cm-1). In contrast, [Cr(C6Me3H3)2][TCNQ] does not obey the Curie-Weiss law but can be fit to an expression that accounts for contributions from independent Curie spins for the cation and a thermally activated triplet state for the dimerized anions [ΔE = 315 K, 0.027 eV, 219 cm-1, 0.44 kcal/mol]. © 1990 American Chemical Society. |
| first_indexed | 2024-03-07T04:43:31Z |
| format | Journal article |
| id | oxford-uuid:d278246b-7a11-4673-9f3c-a47df0a05918 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:43:31Z |
| publishDate | 1990 |
| record_format | dspace |
| spelling | oxford-uuid:d278246b-7a11-4673-9f3c-a47df0a059182022-03-27T08:04:05ZLOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].-Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d278246b-7a11-4673-9f3c-a47df0a05918EnglishSymplectic Elements at Oxford1990Ohare, DWard, MMiller, JThe reaction of donor, Cr(arene)2 (arene = C6Me6 and C6Me3H3), D, with the acceptor TCNQ, A, results in formation of electron-transfer salts of [D].+[A].- composition. Two phases of [Cr(C6Me3H3)2] .+[TCNQ].- have been structurally characterized. The α-phase belongs to the centrosymmetric C2/c space group [a = 14.014 (4) Å, b = 16.347 (4) Å, c = 22.964 (6) Å, β = 107.44 (2)°, Z = 8, V = 5019 (5) Å3, T = 23°C, R = 0.082] with the solid-state structure consisting of ⋯D.+D.+A22-D .+D.+⋯ linear chains. Each [TCNQ]- in the [TCNQ]22- dimer is planar, and the intradimer separation is 3.47 Å. The anion-anion overlap is unusual as the dihedral angle between the planes normal to the long molecular axes is 31°. The β-phase crystallizes in the P21/c space group [a = 9.588 (5) Å, b = 16.390 (3) Å, c = 8.419 (6) Å, β = 106.84 (6)°, Z = 2, V = 1266 (9) Å3, T = 23°C, R = 0.044] with the solid-state structure consisting of ⋯D.+A.-D.+A.-⋯ linear chains. The magnetic susceptibility of α- [Cr(C6Me6)2] [TCNQ] obeys the Curie-Weiss law with an effective moment, μeff, of 1-77 μB and θ of -0.1 K. This is consistent with the presence of a diamagnetic [TCNQ]22- dimer (v(C≡N) = 2156 m, 2175 s, and 2182 s cm-1). In contrast, [Cr(C6Me3H3)2][TCNQ] does not obey the Curie-Weiss law but can be fit to an expression that accounts for contributions from independent Curie spins for the cation and a thermally activated triplet state for the dimerized anions [ΔE = 315 K, 0.027 eV, 219 cm-1, 0.44 kcal/mol]. © 1990 American Chemical Society. |
| spellingShingle | Ohare, D Ward, M Miller, J LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].- |
| title | LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].- |
| title_full | LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].- |
| title_fullStr | LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].- |
| title_full_unstemmed | LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].- |
| title_short | LOW-DIMENSIONAL ORGANOMETALLIC ELECTRON-TRANSFER COMPLEXES - X-RAY STRUCTURES AND MAGNETIC-PROPERTIES OF ALPHA-[CR(C6ME3H3)2].+[TCNQ].- AND BETA-[CR(C6ME3H3)2].+[TCNQ].- |
| title_sort | low dimensional organometallic electron transfer complexes x ray structures and magnetic properties of alpha cr c6me3h3 2 tcnq and beta cr c6me3h3 2 tcnq |
| work_keys_str_mv | AT ohared lowdimensionalorganometallicelectrontransfercomplexesxraystructuresandmagneticpropertiesofalphacrc6me3h32tcnqandbetacrc6me3h32tcnq AT wardm lowdimensionalorganometallicelectrontransfercomplexesxraystructuresandmagneticpropertiesofalphacrc6me3h32tcnqandbetacrc6me3h32tcnq AT millerj lowdimensionalorganometallicelectrontransfercomplexesxraystructuresandmagneticpropertiesofalphacrc6me3h32tcnqandbetacrc6me3h32tcnq |