Refinement of the crystal structure of acetylacetonatodicarbonylrhodium(I)

Huq, Fazlul; Skapski, A. C.

doi:10.1007/bf01220097

Cited by 70 publications

(34 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We here give one representative example complex from the test set, Rh(acac)(CO) 2 , a precursor of the catalyst in hydroformylation ( Figure 2). The calculated structural parameters are in excellent agreement with the experiment from X-ray structural analysis [27]. Both shown bond lengths (rhodium-CO and C-O) are better reproduced by BP86 (to within 0.01 Å), whereas B3LYP overestimates the Rh-C bonds by 0.3 Å, and underestimates C=O distances by 0.05 Å.…”

Section: Resultssupporting

confidence: 73%

See 1 more Smart Citation

VIBRATIONAL SCALING FACTORS FOR Rh(I) CARBONYL COMPOUNDS IN HOMOGENEOUS CATALYSIS

Kohls¹,

Stein²

2017

Contributions

View full text Add to dashboard Cite

Metal carbonyl complexes are an important family of catalysts in homogeneous industrial processes. Their characteristic vibrational frequencies allow in situ tracking of catalytic progress. Structural assignment of intermediates is often hampered by the lack of appropriate reference compounds. The calculation of carbonyl vibrational frequencies from first principles provides an alternative tool to identify such reactive intermediates. Scaling factors for computed vibrational carbonyl stretching frequencies were derived from a training set of 45 Rh-carbonyl complexes using the BP86 and B3LYP functionals. The systematic scaling of the computed C=O frequencies yields accurate calculation and assignment of the experimentally obtained (CO) values. The vibrational scaling factors can be used to identify reaction intermediates of the industrially relevant Rh-catalyzed hydroformylation reaction. The absolute error between calculated and experimental spectra was significantly reduced and the experimental spectra were assigned successfully.

show abstract

Section: Resultssupporting

confidence: 73%

“…Comparison of experimentally obtained structure [27] of Rh(acac)(CO) 2 to the calculated ones on BP86/def2-TZVP and B3LYP/def2-TZVP levels of theory.…”

Section: Figurementioning

confidence: 99%

VIBRATIONAL SCALING FACTORS FOR Rh(I) CARBONYL COMPOUNDS IN HOMOGENEOUS CATALYSIS

Kohls¹,

Stein²

2017

Contributions

View full text Add to dashboard Cite

show abstract

“…These interactions are the dominant force governing the packing of the molecules within the crystal structure. In contrast with previous structures the metallophillic interactions are only observed between two neighbouring rhodium centres and does not extend to form ainfinite chain as reported for similar complexes [10,13]. …”

contrasting

confidence: 49%

“…Therhodium complex reported here showed stacking in such away that the rhodium atomsofneighbouring complexes interact almost perpendicular to the coordination polyhedron, with Rh×××Rh distances of 3.124(2) Å. These values are slighly shorter than the Rh×××Rh distances reported for [Rh(acac)(CO) 2 ] (3.253a nd 3.271 Å) [13]. For the benzoyl-1,1,1-trifluoroacetonatodicarbonylrhodium(I) complex these distances were reported as 3.537 Å [14].Neighboring complexes arrange in ahead to tail mode with areported angle of 94.52°between the polyhedra of the rhodium centres.…”

Section: Discussionmentioning

confidence: 42%

Crystal structure of acetopyruvato-κ2O,O'-dicarbonylrhodium(I), C8H7O6Rh

Pretorius

Brink

Roodt

2014

Zeitschrift Für Kristallographie - New Crystal Structures

View full text Add to dashboard Cite

Source of materialRhCl 3 ×3H 2 O(0.011 g, 0.043 mmol) was refluxed in 2mlofDMF until the red colour was observed to turn ab rilliant yellow (approx. 30 min). The solution was then cooled in an ice-bath before adding acetopyruvate (0.00738 g, 0.0512 mmol) to the reaction mixture. The yellow product was precipitated by the addition of ice-waterand wasthencollected bycentrifugation. Experimental detailsThemethylHatomswere placed in geometricallyidealized positionsand constrainedtorideontheir parent atoms,with C-H = 0.95 Åa nd U iso (H) =1 .5U eq (C). Theh ighest residual electron density waslocated 0.74 ÅfromRh1 andthe deepest hole was 0.85 Åfrom Rh1. DiscussionRhodium is one of the most studied transition metals due to its importance in various applications including catalysis and biological activity [1,2]. Our interest in rhodium chemistry forms part of an over-arching investigation into steric manipulation of various transition metal complexes for application in catalysis, radiopharmaceutical and separation technology [3][4][5][6][7][8][9][10].The title complex displays atypical square planar geometry with the rhodium centre surrounded by two carbonyl and a b-diketonato ligand. No significant distortion of the geometry is observed with the rhodium centre situated amere 0.046 Åabove the basal plane. There exists oxygen-oxygen contacts determined as 2.978(1) Åb etween the carbonyl groups of neighbouring molecules in aheadto-head configuration. Metallophilic interaction was observed between the rhodium centres of the molecules in the solid state. Metallophilicity hasbeendefined as theinteraction betweenelectron densitiesoflarge metal centres with an associated energy in thesameorderashydrogen-bonding [11].These metallophilic interactions often lead to the construction of 1-D metal chains and have been widely recognized for other square-planar Rh(I) molecules [12]. Therhodium complex reported here showed stacking in such away that the rhodium atomsofneighbouring complexes interact almost perpendicular to the coordination polyhedron, with Rh×××Rh distances of 3.124(2) Å. These values are slighly shorter than the Rh×××Rh distances reported for [Rh(acac)(CO) 2 ] (3.253a nd 3.271 Å) [13]. For the benzoyl-1,1,1-trifluoroacetonatodicarbonylrhodium(I) complex these distances were reported as 3.537 Å [14].Neighboring complexes arrange in ahead to tail mode with areported angle of 94.52°between the polyhedra of the rhodium centres. These interactions are the dominant force governing the packing of the molecules within the crystal structure. In contrast with previous structures the metallophillic interactions are only observed between two neighbouring rhodium centres and does not extend to form ainfinite chain as reported for similar complexes [10,13].

show abstract

“…Its anion acts as the bidentate ligand and is known to form complexes with many transition metal ions [3][4][5]. A general method of preparation of such complexes consists in a reaction of a metal ion with acetylacetone in presence of a base which easily separates the proton.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Antibacterial Studies and Crystal Structures of Tridentate Schiff Base Ligand and It’s Cobalt(III) Complex

et al. 2012

View full text Add to dashboard Cite

The crystal structures of 4-[(2-hydroxyphenyl) imino]-2-pentanone (H 2 hpac, 1) and its cobalt(III) complex [Co III (hpac)py 3 ] ? ÁPF 6 -(2) have been determined by X-ray diffraction. The ligand 1 crystallizes in orthorhombic chiral P2 1 2 1 2 1 space group, with a = 8.8405(4) Å , b = 10.5349(8) Å , c = 11.2292)7( Å ), and the complex 2-in the centrosymmetric monoclinic P2/n space group, with a = 16.496(5) Å , b = 10.171(2) Å , c = 16.646(5) Å , and b = 95.53(3)°. In the ligand molecule quite strong intramolecular hydrogen bond closes six-membered ring. The bond length pattern within this ring suggests the significant conjugation and the structure might be therefore regarded as the intermediate between keto-enamine and zwitterionic forms, and the intramolecular hydrogen bond falls into category of resonance-assisted hydrogen bonds. In turn, intermolecular O-HÁÁÁO hydrogen bonds connect the molecules of the ligand into infinite chains along [100] direction. In the complex, the Co(III) ion is hexa-coordinated, by two oxygen and one nitrogen atoms of the doubly-deprotonated ligand 1 and by three nitrogen atoms from three pyridine ligands. The coordination polyhedron is close to a slightly distorted octahedron. The in vitro antimicrobial activity of the Schiff base ligand and its corresponding complex have been tested against human pathogenic bacterias such as Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli.Keywords Schiff base Á Tridentate ligands Á Co complex Á Hydrogen bonds Á Biological activity Results and DiscussionAcetylacetone (acac) or pentane-2,4-dione is often used as a good precursor in organic synthesis and as a building block of metal-organic complexes [1,2]. Its anion acts as the bidentate ligand and is known to form complexes with many transition metal ions [3][4][5]. A general method of preparation of such complexes consists in a reaction of a metal ion with acetylacetone in presence of a base which easily separates the proton. Replacement of the ketone functional group by the imine one results in corresponding bidentate Schiff bases, which also proved to be useful ligands. If 2-hydroxy aniline is used as the amine, one can prepare the tridentate ligand. Such a ligand-4-[(2-hydroxyphenyl)imino]-2-pentanone (hereafter referred to as 1), known as H 2 hpac, where H 2 represents the dissociable enolic -OH and hydroxyphenyl protons-has been already prepared and used for making the square-planar mixed-ligand nickel(II) complex with deprotonated H 2 hpac (i.e. hpac), which coordinates through the enolate oxygen, the imine nitrogen and the deprotonated hydroxyphenyl oxygen atoms. Additionally, the neutral N-donor, imidazole, has been used as an ancillary ligand [6]. Such

show abstract

Refinement of the crystal structure of acetylacetonatodicarbonylrhodium(I)

Cited by 70 publications

References 15 publications

VIBRATIONAL SCALING FACTORS FOR Rh(I) CARBONYL COMPOUNDS IN HOMOGENEOUS CATALYSIS

VIBRATIONAL SCALING FACTORS FOR Rh(I) CARBONYL COMPOUNDS IN HOMOGENEOUS CATALYSIS

Crystal structure of acetopyruvato-κ2O,O'-dicarbonylrhodium(I), C8H7O6Rh

Synthesis, Antibacterial Studies and Crystal Structures of Tridentate Schiff Base Ligand and It’s Cobalt(III) Complex

Contact Info

Product

Resources

About