Bis(imino)pyridine Iron Dinitrogen Compounds Revisited : Differences in Electronic Structure Between Four- and Five-Coordinate Derivatives

The electronic structures of the four- and five-coordinate aryl-substituted bis(imino)pyridine iron dinitrogen complexes, ((iPr)PDI)FeN(2) and ((iPr)PDI)Fe(N(2))(2) ((iPr)PDI = 2,6-(2,6-(i)Pr(2)-C(6)H(3)-N=CMe)(2)C(5)H(3)N), have been investigated by a combination of spectroscopic techniques (NMR, M...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Organometallics. - 1998. - 31(2012), 6 vom: 26. März, Seite 2275-2285
1. Verfasser: E Stieber, S Chantal (VerfasserIn)
Weitere Verfasser: Milsmann, Carsten, Hoyt, Jordan M, Turner, Zoë R, Finkelstein, Kenneth D, Wieghardt, Karl, Debeer, Serena, Chirik, Paul J
Format: Aufsatz
Sprache:English
Veröffentlicht: 2012
Zugriff auf das übergeordnete Werk:Organometallics
Schlagworte:Journal Article
LEADER 01000caa a22002652 4500
001 NLM218421486
003 DE-627
005 20240412232136.0
007 tu
008 231224s2012 xx ||||| 00| ||eng c
028 5 2 |a pubmed24n1373.xml 
035 |a (DE-627)NLM218421486 
035 |a (NLM)22675236 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a E Stieber, S Chantal  |e verfasserin  |4 aut 
245 1 0 |a Bis(imino)pyridine Iron Dinitrogen Compounds Revisited  |b Differences in Electronic Structure Between Four- and Five-Coordinate Derivatives 
264 1 |c 2012 
336 |a Text  |b txt  |2 rdacontent 
337 |a ohne Hilfsmittel zu benutzen  |b n  |2 rdamedia 
338 |a Band  |b nc  |2 rdacarrier 
500 |a Date Revised 12.04.2024 
500 |a published: Print-Electronic 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a The electronic structures of the four- and five-coordinate aryl-substituted bis(imino)pyridine iron dinitrogen complexes, ((iPr)PDI)FeN(2) and ((iPr)PDI)Fe(N(2))(2) ((iPr)PDI = 2,6-(2,6-(i)Pr(2)-C(6)H(3)-N=CMe)(2)C(5)H(3)N), have been investigated by a combination of spectroscopic techniques (NMR, Mössbauer, X-ray Absorption and X-ray Emission) and DFT calculations. Homologation of the imine methyl backbone to ethyl or isopropyl groups resulted in the preparation of the new bis(imino)pyridine iron dinitrogen complexes, ((iPr)RPDI)FeN(2) ((iPr)RPDI = 2,6-(2,6-(i)Pr(2)-C(6)H(3)-N=CR)(2)C(5)H(3)N; R = Et, (i)Pr), that are exclusively four coordinate both in the solid state and in solution. The spectroscopic and computational data establish that the ((iPr)RPDI)FeN(2) compounds are intermediate spin ferrous derivatives (S(Fe) = 1) antiferromagnetically coupled to bis(imino)pyridine triplet diradical dianions (S(PDI) = 1). While this ground state description is identical to that previously reported for ((iPr)PDI)Fe(DMAP) (DMAP = 4-N,N-dimethylaminopyridine) and other four-coordinate iron compounds with principally σ-donating ligands, the d-orbital energetics determine the degree of coupling of the metal-chelate magnetic orbitals resulting in different NMR spectroscopic behavior. For ((iPr)RPDI)Fe(DMAP) and related compounds, this coupling is strong and results in temperature independent paramagnetism where a triplet excited state mixes with the singlet ground state via spin orbit coupling. In the ((iPr)RPDI)FeN(2) family, one of the iron SOMOs is essentially d(z2) in character resulting in poor overlap with the magnetic orbitals of the chelate, leading to thermal population of the triplet state and hence temperature dependent NMR behavior. The electronic structures of ((iPr)RPDI)FeN(2) and ((iPr)PDI)Fe(DMAP) differ from ((iPr)PDI)Fe(N(2))(2), a highly covalent molecule with a redox non-innocent chelate that is best described as a resonance hybrid between iron(0) and iron(II) canonical forms as originally proposed in 2004 
650 4 |a Journal Article 
700 1 |a Milsmann, Carsten  |e verfasserin  |4 aut 
700 1 |a Hoyt, Jordan M  |e verfasserin  |4 aut 
700 1 |a Turner, Zoë R  |e verfasserin  |4 aut 
700 1 |a Finkelstein, Kenneth D  |e verfasserin  |4 aut 
700 1 |a Wieghardt, Karl  |e verfasserin  |4 aut 
700 1 |a Debeer, Serena  |e verfasserin  |4 aut 
700 1 |a Chirik, Paul J  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Organometallics  |d 1998  |g 31(2012), 6 vom: 26. März, Seite 2275-2285  |w (DE-627)NLM098167103  |x 0276-7333  |7 nnns 
773 1 8 |g volume:31  |g year:2012  |g number:6  |g day:26  |g month:03  |g pages:2275-2285 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_350 
951 |a AR 
952 |d 31  |j 2012  |e 6  |b 26  |c 03  |h 2275-2285