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Electron‐Rich Fe and Ru Complexes with the New Trisamine Dithiolate Ligand ′N 3 H 3 S 2 ′‐H 2 [2,2′‐Bis(2‐mercaptophenylamino)diethylamine]
Author(s) -
Sellmann Dieter,
Utz Jürgen,
Heinemann Frank W.
Publication year - 1999
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(19990202)1999:2<341::aid-ejic341>3.0.co;2-v
Subject(s) - chemistry , deprotonation , diethylamine , protonation , ruthenium , ligand (biochemistry) , medicinal chemistry , electron paramagnetic resonance , substitution reaction , amine gas treating , crystallography , stereochemistry , photochemistry , catalysis , organic chemistry , ion , biochemistry , physics , receptor , nuclear magnetic resonance
In order to obtain iron and ruthenium complexes which are analogous to [M(L)(′NHS 4 ′)] and [M(L)(′N 2 H 2 S 3 ′)] complexes [′NHS 4 ′ 2– = 2,2′‐bis(2‐mercaptophenylthio)diethylamine(2–), ′N 2 H 2 S 3 ′ 2– = 2,2′‐bis(2‐mercaptophenylamino)diethylsulfide(2–)] but have electron‐richer metal centers, the new pentadentate amine thiolate ligand ′N 3 H 3 S 2 ′‐H 2 [ = 2,2′‐bis(2‐mercaptophenylamino)diethylamine] ( 4 ) was synthesized. The dianion ′N 3 H 3 S 2 ′ 2– reacted with Fe II salts to give high‐spin [Fe(′N 3 H 3 S 2 ′)] ( 5 ) [μ eff (293 K) = 3.94 μ B ], which yielded diamagnetic [Fe(CO)(′N 3 H 3 S 2 ′)] ( 6 ) upon reaction with CO. Complex 6 exhibits a low‐frequency ν(CO) band (1934 cm −1 in THF) indicating an electron‐rich Fe center and a strong Fe–CO bond. In spite of this, 6 readily dissociated in solution to 5 and CO. The reaction of [RuCl 2 (PPh 3 ) 3 ] with ′N 3 H 3 S 2 ′ 2– yielded [Ru(PPh 3 )(′N 3 H 3 S 2 ′)] ( 7 ), which proved inert with respect to PPh 3 substitution but could be methylated at the thiolate donors. The resulting [Ru(PPh 3 )(′N 3 H 3 S 2 ′‐Me 2 )]I 2 ( 8 ) proved as inert towards substitution as 7 . Complex 8 could reversibly be deprotonated to give [Ru(PPh 3 )(′N 3 H 2 S 2 ′‐Me 2 )]I ( 11 ), in the course of which the [RuPN 3 S 2 ] cores rearrange from C S to C 1 symmetry. Reversible protonation/deprotonation was also found with [Ru(NO)(′N 3 H 2 S 2 ′)] ( 9 ) which formed from [RuCl 3 (NO)(PPh 3 ) 2 ] and ′N 3 H 3 S 2 ′ 2– in the presence of one additional equivalent of LiOMe. Protonation of 9 with HBF 4 gave [Ru(NO)(′N 3 H 3 S 2 ′)]BF 4 ( 10 ). The NMR spectra and the X‐ray structure analysis of 8 proved that the [RuPN 3 S 2 ] cores of 7 and 8 exhibit a C S ‐symmetrical meso structure. In all other complexes, however, the [MLN 3 S 2 ] cores exhibit a C 1 ‐symmetrical structure. It results from the fac ‐ mer coordination mode of the ′N 3 H 3 S 2 ′ 2– ligand and favors the planarization of amide donors when NH functions are reversibly deprotonated.