Coordination of an Imine Ligand on an Os<sub>3</sub>Cluster Stabilized by Intramolecular Os−H---H−N Hydrogen Bonding

Aime, Silvio; Férriz, Marta; Gobetto, Roberto; Valls, Esteve

doi:10.1021/om980885b

Cited by 28 publications

(40 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Pure product was obtained by recrystallization of the residue with dichloromethane/hexane. Yield: 0.48 g (87% 4 were dissolved in CD 2 Cl 2 in an NMR tube, and a limited amount of HBF 4 ⋅Et 2 O was then added. The 1 H-NMR spectrum was immediately taken at -60°C.…”

Section: Trispyrazolylmethane (Tpm)mentioning

confidence: 99%

See 1 more Smart Citation

Protonation of [tpmRu(PPh3)2H]BF4 [tpm = Tris(pyrazolyl)methane] – Formation of Unusual Hydrogen-Bonded Species

Chu

et al. 2000

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

in CD2Cl2 yielded, in a straightforward manner, the dicationic η2‐dihydrogen complex [tpmRu(PPh3)2(H2)](BF4)2, which, as expected, is more acidic than its monocationic Tp [Tp = hydrotris(pyrazolyl)borate] analog [TpRu(PPh3)2(H2)]BF4 (pKa: 2.8 vs. 7.6). The complex [tpmRu(PPh3)2(H2)](BF4)2 is unstable towards H2 loss at ambient temperature. However, acidification of [tpmRu(PPh3)2H]BF4 with excess aqueous HBF4 or aqueous triflic acid in [D8]THF gave very interesting results. Variable‐temperature 1H‐ and 31P‐NMR studies revealed that the aqueous acid did not fully protonate the metal hydride to form the dihydrogen complex, but a hydrogen‐bonded species was obtained. The feature of this species is that the strength of its Ru–H···H–(H2O)m interaction decreases with temperature; this phenomenon is unusual because other complexes containing dihydrogen bonds show enhanced M–H···H–X interaction as the temperature is lowered. Decrease of the dihydrogen‐bond strength with temperature in the present case can be attributed to the decline of acidity that results from the formation of larger H+(H2O)n (n > m) clusters at lower temperatures; steric hindrance of these large clusters also contribute to the weakening of the dihydrogen bonding interactions. At higher temperatures, facile H/H exchange occurs in Ru–H···H–(H2O)m via the intermediacy of a “hydrogen‐bonded dihydrogen complex” Ru–(H2)···(H2O)m. To investigate the effect of the H+(H2O)m cluster size on the strength of the dihydrogen bonding in [tpmRu(PPh3)2H]+, molecular orbital calculations at the B3LYP level have been performed on model systems, [tpmRu(PH3)2H]+ + H+(H2O) and [tpmRu(PH3)2H]+ + H+(H2O)2. The results provide further support to the notion that the formation of larger H+(H2O)n clusters weakens the Ru–H····H(H2O)n dihydrogen bonding interaction.

show abstract

Section: Trispyrazolylmethane (Tpm)mentioning

confidence: 99%

“…A sample of [tpmRu(PPh 3 ) 2 H]BF 4 (1) (10 mg, 0.011 mmol) was dissolved in 0.4 mL of [D 8 ]THF in a 5-mm NMR tube, and 10 µL of aqueous HBF 4 (8 ) was added. The VT 1 H-NMR spectra were immediately taken.…”

Section: Protonation Of [Tpmru(pph 3 ) 2 H]bf 4 (1) With Aqueous Hbfmentioning

confidence: 99%

Protonation of [tpmRu(PPh3)2H]BF4 [tpm = Tris(pyrazolyl)methane] – Formation of Unusual Hydrogen-Bonded Species

Chu

et al. 2000

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…Most of the systems involving M -H¯H-N bonds considered so far contain sp 3 hybridized N and M (AϭB, Al, etc.͒. Very recently, Aime and co-workers 29,45,46 reported Os-H¯H-N bonds where imine ligands ͑such as HNvCPh 2 and HNvCHCH 3 ) are coordinated with an osmium complex. Different H¯H distances have been reported by these authors, such as 1.79 Å in the crystal structure ͑x-ray data͒ and 2.00 Å in solution ͑NMR data͒.…”

Section: Introductionmentioning

confidence: 99%

Comparison between hydrogen and dihydrogen bonds among H3BNH3, H2BNH2, and NH3

Kar¹,

Scheiner²

2003

The Journal of Chemical Physics

View full text Add to dashboard Cite

Several possible binary complexes among ammonia-borane, aminoborane, and ammonia, via hydrogen and/or dihydrogen bonds, have been investigated to understand the effect of different hybridization. Møller-Plesset second-order perturbation theory with aug-cc-pVDZ basis set was used. The interaction energy is corrected for basis set superposition error, and the Morokuma-Kitaura method was employed to decompose the total interaction energy. Like H 3 BNH 3 , the sp 2 hybridized H 2 BNH 2 also participates in Hand dihydrogen bond formation. However, such bonds are weaker than their sp 3 analogs. The contractions of BN bonds are associated with blueshift in vibrational frequency and stretches of BH and NH bonds with redshift. The polarization, charge transfer, correlation, and higher-order energy components are larger in dihydrogen bonded complexes, compared to classical H-bonded ammonia dimers.

show abstract

“…[12b] However, the fact that [Os 3 (µ-H) 2 (CO) 10 ] does not react with H 2 dan under thermal conditions seems somewhat surprising as this unsaturated cluster is very reactive. [12c] Indeed, it has been reported that the saturated adducts [Os 3 H(µ-H)(CO) 10 (L)] (L ϭ NH 3 , NH 2 R, NHR 2 ) can be prepared at room temperature by treating [Os 3 (µ-H) 2 (CO) 10 ] with ammonia gas either in the solid state [13] or in solution, [14] or with primary and secondary amines in solution. [15] In the case of H 2 dan, the existence of intramolecular hydrogen bonding involving both NH 2 groups may account for its lower reactivity as compared with that of other amines.…”

Section: Discussionmentioning

confidence: 99%

Reactivity of Triosmium Carbonyl Clusters with 1,8-Diaminonaphthalene − Synthesis and Structural Characterization of Amido, Diamido, andC-Metalated Trinuclear Derivatives

Cabeza¹,

Nöth²,

Rosales-Hoz³

et al. 2000

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

The compounds [Os3(CO)12] and [Os3(μ‐H)2(CO)10] do not react with 1,8‐diaminonaphthalene (H2dan) under thermal conditions (110 °C, 30 min). However, [Os3(CO)10(MeCN)2] reacts with H2dan (THF, reflux temperature) to give two isomers of [Os3(μ‐H)(μ‐Hdan)(CO)9] (1 and 2). In toluene at reflux temperature, these reagents afford [Os3(μ‐dan)(CO)10] (3). Compound 2 can be converted into 3 under thermal conditions, but no interconversion between 1 and 2 has been observed. The three compounds have been characterized by X‐ray diffraction methods. Compound 1 arises from the C‐metalation of H2dan in a position adjacent to an NH2 group; this generates a hydride and a ligand that interacts with the three metal atoms through one of the NH2 groups, through the metalated carbon atom (which spans an Os−Os edge), and through one of the C=C bonds of the metalated ring. In compound 2, the hydride arises from the oxidative addition of an N−H bond of H2dan; the resulting ligand interacts with two of the three metal atoms through the amido NH fragment (bridging position) and through the remaining NH2 group. Compound 3 is derived from the transformation of both NH2 groups of H2dan into amido NH groups and consists of a 50‐electron trinuclear cluster with the longest edge doubly‐bridged by both amido groups.

show abstract

Coordination of an Imine Ligand on an Os₃Cluster Stabilized by Intramolecular Os−H---H−N Hydrogen Bonding

Cited by 28 publications

References 25 publications

Protonation of [tpmRu(PPh3)2H]BF4 [tpm = Tris(pyrazolyl)methane] – Formation of Unusual Hydrogen-Bonded Species

Protonation of [tpmRu(PPh3)2H]BF4 [tpm = Tris(pyrazolyl)methane] – Formation of Unusual Hydrogen-Bonded Species

Comparison between hydrogen and dihydrogen bonds among H3BNH3, H2BNH2, and NH3

Reactivity of Triosmium Carbonyl Clusters with 1,8-Diaminonaphthalene − Synthesis and Structural Characterization of Amido, Diamido, andC-Metalated Trinuclear Derivatives

Contact Info

Product

Resources

About

Coordination of an Imine Ligand on an Os3Cluster Stabilized by Intramolecular Os−H---H−N Hydrogen Bonding

Cited by 28 publications

References 25 publications

Protonation of [tpmRu(PPh3)2H]BF4 [tpm = Tris(pyrazolyl)methane] – Formation of Unusual Hydrogen-Bonded Species

Protonation of [tpmRu(PPh3)2H]BF4 [tpm = Tris(pyrazolyl)methane] – Formation of Unusual Hydrogen-Bonded Species

Comparison between hydrogen and dihydrogen bonds among H3BNH3, H2BNH2, and NH3

Reactivity of Triosmium Carbonyl Clusters with 1,8-Diaminonaphthalene − Synthesis and Structural Characterization of Amido, Diamido, andC-Metalated Trinuclear Derivatives

Contact Info

Product

Resources

About

Coordination of an Imine Ligand on an Os₃Cluster Stabilized by Intramolecular Os−H---H−N Hydrogen Bonding