13. Tetranuclear Mixed‐Metal Clusters

Geoffroy, Gregory L.; Fox, J.; Burkhardt, Eric W.; Foley, Henry C.; Harley, A. Dale; Rosen, Richard P.; Fjare, Douglas E.; Furuya, Frederic R.; Hull, John W.; Stevens, Robert E.; Gladfelter, Wayne L.

doi:10.1002/9780470132524.ch13

Cited by 18 publications

(2 citation statements)

References 11 publications

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“…The authors failed to separate the isomers chromatographically, and all spectral data presented were attributed to a mixture of forms coexisting in solution. The spectral characteristics of this mixture, according to the results of 31 The authors 45 claimed that the forms of the cluster with phosphine coordination at the ruthenium and osmium atoms, which were found upon crystallization of the com pound, should be considered as isomers in this system. The fast dynamic process observed in the 1 H NMR spec trum at room temperature is the phosphine transfer be tween the osmium and ruthenium atoms.…”

Section: Methodsmentioning

confidence: 98%

Structure and dynamic properties of substituted carbonylhydride clusters H2RuOs3(CO)13 and H4Ru4(CO)12 containing functionalized phosphines

et al. 2007

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The derivatives of the H 2 RuOs 3 (CO) 13 and H 4 Ru 4 (CO) 12 carbonylhydride clusters con taining functionalized (including chiral) phosphines were synthesized. The solid state struc ture of H 2 RuOs 3 (CO) 12 (Ph 2 P(C 4 H 3 S)) was determined by X ray diffraction analysis. The structures of other compounds in solution were determined using IR and 1 H and 31 P NMR spectroscopy. A study of the temperature dependences of the 1 H NMR spectra of the phos phine substituted tetrahedral clusters along with the analysis of literature data for their analogs showed that compounds of this type exist in solution as an equilibrium mixture of isomers, which differ in arrangement of the hydride ligands at the cluster skeleton. Interconversion of the isomeric forms is due to migration of the hydride ligands over the cluster skeleton. A general model for this dynamic process was proposed. The model is consistent with both our data and earlier results of other authors.Carbonylhydride clusters of the iron subgroup transi tion metals are used as efficient catalysts in hydrogena tion of unsaturated organic compounds. 1-4 From this point of view, it seems most attractive to consider phos phine substituted derivatives of the H 4 Ru 4 (CO) 12 and H 2 RuOs 3 (CO) 12 clusters, whose activity in various or ganic reactions is well known. 1-14 Reactions of asymmet ric synthesis 15 are especially interesting from the theoreti cal and applied viewpoints, and reactions of this type catalyzed by cluster compounds have been most poorly studied up to date, and only restricted examples of using the clusters in asymmetrical catalysis are available in the literature. 16-18As a rule, in the organometallic complexes of this type the hydride ligands participate in the low barrier dynamic processes, such as hydride migration over the cluster skeleton in solution 19-24 and even in the solid phase. 25-27 The fast intramolecular hydride exchange in the cluster compounds in solution has been evidenced for the first time for a series of compounds H 4 Ru 4 (CO) 12-x L x (L = P(OMe 3 ), x = 1-4). 28 However, subsequent more detailed studies 22,29 of the structure of the ligand environment and mechanism of dynamic processes in these compounds revealed no general pattern, and some conclusions of the above cited works even contradict each other.In this work, we synthesized new tetrahedral mono substituted carbonylhydride clusters with functional ized phosphine ligands H 2 RuOs 3 (CO) 12 (PS) (1) and H 4 Ru 4 (CO) 11 L (2-5), where L = POx (2), PSug (3), PInd (4), and PStyr (5); PS is thienyldiphenylphosphine, POx is (1R,9R)[2(oxymethylquinolisidinyl)ethyl]di(2 phenylethyl)phosphine, PSug is (2 [5 (2,2 dimethyl 1,3 dioxolan 4 yl) 2,2 dimethyltetrahydrofuro[2,3 d][1,3]di oxol 6 yl]oxyethyl)di(2 phenylethyl)phosphine, PInd is [2 (1 indolyl)propyl]di(2 phenylethyl)phosphine, PStyr is (2 phenylpropyl)distyrylphosphine. The structures of compounds 1-5 in solution were studied, and a model for the dynamic behavior of their coordination sphere was proposed.

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Section: Methodsmentioning

confidence: 98%

Structure and dynamic properties of substituted carbonylhydride clusters H2RuOs3(CO)13 and H4Ru4(CO)12 containing functionalized phosphines

et al. 2007

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“…The high efficiency of the ligand‐stripping process is illustrated in Figure 1, the energy dependent ESIMS/MS8 of [CoRu 3 (CO) 13 ] − 9. Carbonyl ligands are removed from the core as free CO by collision‐induced dissociation (CID) of the cluster ions with an inert target gas (e.g.…”

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confidence: 99%

P26.14: Aortic aneurysm and sternal cleft: A variant of the PHACES syndrome?

Fuchs

Levasseur

Bonanno

et al. 2008

Ultrasound in Obstet & Gyne

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The prognosis largely depends on the degree of RV hypoplasia, the size of the VSD and the place of insertion of the chordae tendinae of the TV in the LV. To the best of our knowledge, this is the first report of prenatal diagnosis of this rare and complex heart defect. Background: Sternal clefts are rare congenital anomalies that may occur in isolation or in association with other structural malformations. The sternal malformation/vascular dysplasia association consists of sternal clefts with hemangiomas of the skin and internal organs. Abnormalities of the sternum have also been described in the PHACES syndrome which consists of posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, and eye abnormalities. Case: We report a case and associated images of an infant prenatally diagnosed with an aortic aneurysm and chest wall deformity. Postnatally, echocardiogram and MRI revealed a large aneurysm of the proximal descending aorta measuring 1.1 × 1.8 cm. The aneurysm began just distal to the origin of the left carotid artery, and a moderate pre-aneurysmal coarctation was noted. The origin of the left subclavian artery was distal to the aneurysm. In addition, partial sternal cleft with agenesis of the manubrium was noted. The intracranial anatomy was normal, and U/S and MRI revealed no hemangiomas of the head and neck vessels. Dermatologic evaluation revealed no evidence of cutaneous hemangiomas. Bronchoscopy revealed no hemangiomas of the respiratory tract. Ophthalmologic exam revealed normal ocular anatomy. Conclusion: Hemangiomas are the hallmark of both the sternal malformation/vascular dysplasia association and PHACES syndrome. We have, however, identified a case of sternal cleft with aortic aneurysm in the absence of cutaneous or visceral hemangiomas. Although these malformations may be unrelated, this case may also represent a variant of the PHACES syndrome. P26.14

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Carbonyls

Wagner¹,

Kaesz²

2000

Kirk-Othmer Encyclopedia of Chemical Technology

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Carbon monoxide forms a host of metal carbonyl complexes, at least one for every transition metal. Mononuclear, polynuclear, and heteronuclear metal carbonyls are all known. The complexes, of general formula M x (CO) y , may be charged or neutral; the metal or metals are in the zero oxidation state. Metal carbonyls are useful as reagents and catalysts in organic synthesis, and play a role in both the Reppe and the oxo processes, as well as in the preparation of synthetic fuels and in vapor deposition of purified metals. The structure and bonding of the metal carbonyls, including that of cluster compounds, follow well‐defined rules. Synthesis of the metal carbonyls usually proceeds either from the reduction of the corresponding metal, initially in the form of a metallic salt, or via condensation of lower molecular weight compounds.

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13. Tetranuclear Mixed‐Metal Clusters

Cited by 18 publications

References 11 publications

Structure and dynamic properties of substituted carbonylhydride clusters H2RuOs3(CO)13 and H4Ru4(CO)12 containing functionalized phosphines

Structure and dynamic properties of substituted carbonylhydride clusters H2RuOs3(CO)13 and H4Ru4(CO)12 containing functionalized phosphines

P26.14: Aortic aneurysm and sternal cleft: A variant of the PHACES syndrome?

Carbonyls

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