Reactivity of Group 6 cationic complexes. Part 5. Photochemical water reduction by a chromium(II) metallorganic system and X-ray crystal and molecular structure of cis- and trans-[Cr(CO)2(-C5Me5){P(OMe)3}2]+

Laser irradiation at 488 nm of a methanol solution of [Mo(CO)3(η-C5Me5){P(OMe)3}]BF4(1) gives [Mo(CO)2(η-C5Me5){P(OMe)3}(MeOH)]BF4(2), as a mixture of cis and trans isomers. Irradiation at 458 nm of methylene chloride or methanol solutions of the corresponding chromium derivative [Cr(CO)3(η-C5Me5){P(OMe)3}] BF4(4) gives a mixture of cis and trans-[Cr(CO)2(η-C5Me5){P(OMe)3}2]BF4(5), together with unidentified products. The solid-state structures of both cis-and trans-(5) were determined by single-crystal X-ray diffraction. The structural models were refined to R= 0.078, (R′= 0.080) for 770 independent reflections [cis-(5)] and to R= 0.046 (R′= 0.049) for 2 439 independent reflections [trans-(5)]. Crystal data: cis-(5), orthorhombic, space group Pbca, a= 17.738(5), b= 26.370(6), c= 11.344(7)Åtrans-(5), monoclinic, space group I2/a, a= 16.167(5), b= 19.814(6), c= 16.106(2)Å, β= 90.20(2)°. Complex (5) photochemically reduces water, being transformed into the chromium(III) cluster [Cr4(µ-OH)6(η-C5Me5)4][BF4]2(6). Quantum-yield data are reported for this process

Reactivity of cationic molybdenum(II) complexes. Part 3. Synthesis of methoxide and carbomethoxide derivatives of -pentamethylcyclopentadienyl–molybdenum(II) and the crystal structure determination of the oxidation product trans-[{Mo(-C5Me5)(O)2}2(µ-O)]

The complex [Mo(CO)3(η-C5Me5){P(OMe)3}]BF4 (1) reacts in methanol solution with Na(OMe) to give a mixture of cis- and trans-[Mo(CO)2(η-C5Me5){P(OMe)3}(CO2Me)](3). Compound (3) decarbonylates at room temperature in various solvents giving a mixture of cis- and trans-[Mo(CO)2(η-C5Me5){P(OMe)3}(OMe)] (4). The complex [Mo(CO)3(η-C5Me5)] BF4 (2) reacts in methanol solution with Na(OMe) affording the insoluble complex [{Mo(CO)2(η-C5Me5)(OMe)}n] (5) which is monomerized by reaction with P(OMe)3 in refluxing tetrahydrofuran (thf); trans-(4) is the main product of this reaction. Oxidation of a thf suspension of [{Mo(CO)2(η-C5Me5)(OMe)}n] by oxygen gives the Mo(VI) derivative [{Mo(η-C5Me5)(O)2}2(µ-O)] (6), together with unidentified products. The X-ray crystal structure of (6) has been established: (6) is monoclinic, space group P21/a, a= 17.677(6), b= 9.248(1), c= 21.272(6)Å, β= 101.68(2)°, Z= 6

ORGANIZATION OF ALPHA-GLOBIN GENES AND MESSENGER-RNA TRANSLATION IN SUBJECTS CARRYING HEMOGLOBIN HASHARON (ALPHA-47 ASP -] HIS) FROM THE FERRARA REGION (NORTHERN ITALY)

In subjects carrying the haemoglobin Hasharon mutation (alpha 47 replaced by His), originally from the delta of the Po river (Northern Italy), the concentration of the alpha-globin variant has been evaluated and found to be approximately 32%, a value definitely higher than that reported for the same mutant haemoglobin in other regions. Restriction enzyme analysis has been carried out on the DNA from these subjects; the data obtained indicate the presence of three alpha-globin genes per diploid cell. Family studies further show that the two normal genes are located on one chromosome and the Hasharon gene on the other. The origin of the single alpha-gene in the Hasharon-carrying subjects of the Ferrara region is discussed in connection with their haematological and biosynthetic data

ALPHA-THALASSEMIA TRAIT IN THE REGION OF FERRARA

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