Paramagnetic Bis(amidinate) Iron(II) Complexes and their Diamagnetic Dicarbonyl Derivatives

Abstract

Paramagnetic bis(amidinate) iron(II) complexes and their diamagnetic dicarbonyl derivatives Vendemiati, B.

Reductive Coupling of CO Templated by Iron Bound to the Tris(pyrrolide)ethane Scaffold

“…This fragment contains π-bonds conjugated through the pyrrole-oxalyl fragment (see Scheme , 3 ), terminating in an acyl carbon bound to iron (Fe1–C29 = 1.948(3) Å). The two unfunctionalized bound CO molecules display C–O bond lengths of 1.144(3) and 1.150(3) Å, similar to lengths seen for other low-spin Fe 2+ dicarbonyl complexes reported in the literature …”

Reductive Coupling of CO Templated by Iron Bound to the Tris(pyrrolide)ethane Scaffold

“…This fragment contains π-bonds conjugated through the pyrrole-oxalyl fragment (see Scheme , 3 ), terminating in an acyl carbon bound to iron (Fe1–C29 = 1.948(3) Å). The two unfunctionalized bound CO molecules display C–O bond lengths of 1.144(3) and 1.150(3) Å, similar to lengths seen for other low-spin Fe 2+ dicarbonyl complexes reported in the literature …”

Neutral and Cationic Paramagnetic Amino-amidinate Iron(II) Complexes: 19 F NMR Evidence for Interactions with Weakly Coordinating Anions

“…In contrast to 1a , complex 1b does not react with CO under identical conditions. Bis(aminoamidinate) complex 2 also does not react with CO under the applied conditions, whereas the homoleptic amidinate complexes [ t BuC(NR) 2 ] 2 Fe (R = Cy, i Pr) react with CO only to give the bis(carbonyl) adducts [ t BuC(NR) 2 ] 2 Fe(CO) 2 without subsequent CO insertion . This is also the case for the dinuclear amidinate complex {[μ-1,2-[NC(Ph)NSiMe 3 ] 2 - c -C 6 H 10 ]Fe} 2 …”

All-Nitrogen Coordinated Amidinato/Imido Complexes of Molybdenum and Tungsten: Syntheses and Characterization

“…In this case, the solid-state structure seems to be highly different from the symmetric geometry present in solution, where free rotation about the M−N axis because of low sterical hindrance is possible. In summary, differences in the C−N bond lengths in the single-crystal structure greater than 1.8 pm as well as differences between the M−N bond lengths greater than 5 pm suggest an unsymmetrically bonded chelate complex present in solution, leading to separated isopropyl signals in the NMR spectrum. ,, Note that N , N ′-diisopropyl[2,6-bis(mesityl)]benzamidine can be considered as an example of a rare monodentate amidinato complex with M−N and C−N differences of 132.7 and 5.2 pm, respectively.…”

Reductive Coupling of CO Templated by Iron Bound to the Tris(pyrrolide)ethane Scaffold

“…This fragment contains π-bonds conjugated through the pyrrole-oxalyl fragment (see Scheme , 3 ), terminating in an acyl carbon bound to iron (Fe1–C29 = 1.948(3) Å). The two unfunctionalized bound CO molecules display C–O bond lengths of 1.144(3) and 1.150(3) Å, similar to lengths seen for other low-spin Fe 2+ dicarbonyl complexes reported in the literature …”

Neutral and Cationic Paramagnetic Amino-amidinate Iron(II) Complexes: 19 F NMR Evidence for Interactions with Weakly Coordinating Anions

“…In contrast to 1a , complex 1b does not react with CO under identical conditions. Bis(aminoamidinate) complex 2 also does not react with CO under the applied conditions, whereas the homoleptic amidinate complexes [ t BuC(NR) 2 ] 2 Fe (R = Cy, i Pr) react with CO only to give the bis(carbonyl) adducts [ t BuC(NR) 2 ] 2 Fe(CO) 2 without subsequent CO insertion . This is also the case for the dinuclear amidinate complex {[μ-1,2-[NC(Ph)NSiMe 3 ] 2 - c -C 6 H 10 ]Fe} 2 …”

All-Nitrogen Coordinated Amidinato/Imido Complexes of Molybdenum and Tungsten: Syntheses and Characterization

“…In this case, the solid-state structure seems to be highly different from the symmetric geometry present in solution, where free rotation about the M−N axis because of low sterical hindrance is possible. In summary, differences in the C−N bond lengths in the single-crystal structure greater than 1.8 pm as well as differences between the M−N bond lengths greater than 5 pm suggest an unsymmetrically bonded chelate complex present in solution, leading to separated isopropyl signals in the NMR spectrum. ,, Note that N , N ′-diisopropyl[2,6-bis(mesityl)]benzamidine can be considered as an example of a rare monodentate amidinato complex with M−N and C−N differences of 132.7 and 5.2 pm, respectively.…”

Reductive Coupling of CO Templated by Iron Bound to the Tris(pyrrolide)ethane Scaffold

“…This fragment contains π-bonds conjugated through the pyrrole-oxalyl fragment (see Scheme , 3 ), terminating in an acyl carbon bound to iron (Fe1–C29 = 1.948(3) Å). The two unfunctionalized bound CO molecules display C–O bond lengths of 1.144(3) and 1.150(3) Å, similar to lengths seen for other low-spin Fe 2+ dicarbonyl complexes reported in the literature …”

Neutral and Cationic Paramagnetic Amino-amidinate Iron(II) Complexes: 19 F NMR Evidence for Interactions with Weakly Coordinating Anions

“…In contrast to 1a , complex 1b does not react with CO under identical conditions. Bis(aminoamidinate) complex 2 also does not react with CO under the applied conditions, whereas the homoleptic amidinate complexes [ t BuC(NR) 2 ] 2 Fe (R = Cy, i Pr) react with CO only to give the bis(carbonyl) adducts [ t BuC(NR) 2 ] 2 Fe(CO) 2 without subsequent CO insertion . This is also the case for the dinuclear amidinate complex {[μ-1,2-[NC(Ph)NSiMe 3 ] 2 - c -C 6 H 10 ]Fe} 2 …”

All-Nitrogen Coordinated Amidinato/Imido Complexes of Molybdenum and Tungsten: Syntheses and Characterization

“…In this case, the solid-state structure seems to be highly different from the symmetric geometry present in solution, where free rotation about the M−N axis because of low sterical hindrance is possible. In summary, differences in the C−N bond lengths in the single-crystal structure greater than 1.8 pm as well as differences between the M−N bond lengths greater than 5 pm suggest an unsymmetrically bonded chelate complex present in solution, leading to separated isopropyl signals in the NMR spectrum. ,, Note that N , N ′-diisopropyl[2,6-bis(mesityl)]benzamidine can be considered as an example of a rare monodentate amidinato complex with M−N and C−N differences of 132.7 and 5.2 pm, respectively.…”