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M Peruzzini

Publications and source records attributed to M Peruzzini.

4 recordsLinked to original sources
PubMed2000

Cyclotriphosphorus complexes: solid-state structures and dynamic behavior of monoadducts with carbonyl fragments.

Treatment of the cyclo-P3 complexes [(triphos)MP3] [triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane; M = Co (1), Rh (2)] with stoichiometric amounts of [M'(CO)5(thf)]n+ (n = 0, M' = Cr, Mo, W; n = 1, M' = Re) and [W(CO)4(PPh3)(thf)] yields the compounds [[(triphos)M](mu,eta 3:1-P3) [M'(CO)5]] [M = Co; M' = Cr (3a), Mo (3b), W (3c). M = Rh; M' = W (4)], [[(triphos)Co](mu,eta 3:1-P3)[Re(CO5)]]BF4.C7H8 (5) and [[(triphos)Rh](mu,eta 3:1-P3)[W(CO)4PPh3]].2CH2Cl2 (6). The X-ray structures of 5 and 6 have been determined. Crystal data: 5, monoclinic space group P2(1)/n, a = 14.754(2) A, b = 24.886(4) A, c = 15.182(2) A, beta = 103.38(1) degrees, Z = 4; 6, monoclinic space group P2(1)/n, a = 14.872(3) A, b = 27.317(6) A, c = 16.992(4) A, beta = 111.75(5) degrees, Z = 4. The effects of eta 1 coordination on the MP3 core are discussed by comparing the MP3 skeletons in the above structures with those of the previously characterized bis and tris end-on adducts of organometallic fragments of 1. Variable temperature NMR data for the compounds provide evidence for fluxional processes in solution that may be interpreted as [(triphos)M] rotation about its C3 axis and [M'(CO)5] or [M'(CO)4PPh3] scrambling over the P3 cycle. The activation parameters of the fragment scrambling process are determined.

Journal Article↗
PubMed2000

1H- and 2H-T1 relaxation behavior of the rhodium dihydrogen complex [(triphos)Rh(eta 2-H2)H2]+.

Protonation of the classical trihydride [(triphos)RhH3] (2) at 210 K in either THF or CH2Cl2 by either HBF4.OMe2 or CF3SO2OH gives the nonclassical eta 2-H2 complex [(triphos)Rh(eta 2-H2)H2]+ (1) [triphos = MeC(CH2PPh2)3]. Complex 1 is thermally unstable and highly fluxional in solution. In THF above 230 K, 1 transforms into the solvento dihydride complex [(triphos)Rh(eta 1-THF-d8)H2]+ (5) that, at room temperature, quickly converts to the stable dimer trans-[[(triphos)RhH]2(mu-H)2]2+ (trans-6). In CH2Cl2, 1 is stable up to 240 K. Above this temperature, the eta 2-H2 complex begins to convert into a mixture of trans- and cis-6, which, in turn, transform into the bridging-chloride dimers trans- and cis-[[(triphos)RhH]2(mu-Cl)2]2+ at room temperature. Complex 1 contains a fast-spinning H2 ligand with a T1min of 38.9 ms in CD2Cl2 (220 K, 400 MHz). An NMR analysis of the bis-deuterated isotopomer [(triphos)RhH2D2]+ (1-d2) did not provide a J(HD) value. At 190 K, the perdeuterated isotopomers [(triphos)RhD3] (2-d3) and 1-d4 show T1min values of 16.5 and 32.6 ms (76.753 MHz), respectively, for the rapidly exchanging deuterides. An analogous 2-fold elongation of T1min is also observed on going from [(triphos)IrD3] to [(triphos)Ir(eta 2-D2)D2]+. A rationale for the elongation of T1min in nonclassical polyhydrides is proposed on the basis of both the results obtained and recent literature reports.

Journal Article↗
PubMedDate not supplied

[Role of transesophageal echocardiography in the evaluation of the potential embolic risk in left atrial thrombosis. Report of a clinical case].

We describe the case of a 73-year-old man with cardiac failure due to hypertensive heart disease, chronic atrial fibrillation, prior ischemic stroke and acute ischemia of the left leg probably embolic in nature, in whom transthoracic echocardiography (TTE) detected a large left atrial mass compatible with thrombus. Transesophageal echocardiography (TEE) was performed to better evaluate the atrial mass. TTE showed a mass that was firmly attached to the wall of the left atrium, compact, homogeneous and stationary, indicating a relatively low embolic risk. On the other hand TEE clearly detected a marked motility and echographic unhomogeneity of the atrial mass, suggesting a poorer prognosis and urgent surgical referral due to high impending embolik risk. This case further supports the superiority of TEE to TTE in the assessment of intracardiac masses and, in particular, of embolik risk in a patient with left atrial thrombosis.

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