Helmut W. Schmalle

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Two kit preparations of the organometallic precursor [(188)Re(H(2)O)(3)(CO)(3)](+) in aqueous media are presented. Method A uses gaseous carbon monoxide and amine borane (BH(3).NH(3)) as the reducing agent. In method B CO(g) is replaced by K(2)[H(3)BCO(2)] that releases carbon monoxide during hydrolysis. Both procedures afford the desired precursor in(More)
1. Buu-Ho~, N.P., etal.: Bull. Chim. Th~rap. 7, 83 (1972) 2. Brown, R.R., et al.: J. Biol. Chem. 209, 211 (1954) 3. Arcos, J.C., et al. : ibid. 236, 1291 (1961) 4. Conney, A.H., et al.: J. Pharmacol. Exp. Ther. 130, 1 (1960) 5. Buu-Hoi, N.P., Hien, D.P.: C. R. Acad. Sci. 264, 153 (1967) 6. Buu-Hoi, N.P., et al. : ibid. 264, 2414 (1967) 7. Saint-Ruf, G.,(More)
We have prepared four complexes of the type [Re(guanine)(2)(X)(CO)(3)] (guanine = 9-methylguanine or 7-methylguanine, X = H(2)O or Br) in order to understand the factors determining the orientation of coordinated purine ligands around the [Re(CO)(3)](+) core. The 9-methylguanine ligand (9-MeG) was chosen as the simplest N(9) derivatized guanine, and(More)
4 sesquiterpene lactones lacking the exocyclic alpha-methylene at the lactone ring, but possessing further unsaturated centers such as a cyclopentenone ring or an epoxy group, were proved to be sensitizers in guinea pigs. Lack of substitution in the cyclopentenone ring and unsaturation in the side chains appear to be necessary prerequisites for nucleophilic(More)
reduction-reoxidation of the 1-3 system. By comparing the structures 1 and 5, the similarity is bound to the first seven-membered ring, left part of the molecule, while the difference is introduced by the second seven-membered cycle, right part in 5. Thus, the structure 6 is advanced for sarpedorubin A, a parent of phorcarubin (3). As an hypothesis of work,(More)
5,8-Dihydroxyflavone (primetin) has been shown to be the sensitizer in Primula mistassinica Michaux and probably the source of allergic contact dermatitis in four milkers. Its sensitizing properties as determined in guinea-pigs, are strong. As far as is known this is the first experimental demonstration of the sensitizing potency of a flavone. Presumably(More)
The molecular tumor inhibiting titanium compound budotitane [Ti(IV)(bzac)(2)(OEt)(2)] (1) and its dichloro-derivative [Ti(IV)(bzac)(2)Cl(2)] (2) (bzac=1-phenylbutane-1,3-dionate) have been crystallized and characterized by X-ray crystallography and further physical methods. Budotitane (1) crystallizes in the tetragonal, non-centrosymmetric space group P4(1)(More)
The isotopomeric complexes trans-W(Cmesityl)[(C(H,D)3)2PCH2CH2P(C(H,D)3)2]2(H,D) 1-4 were prepared. 2 (W(Cmesityl)(dmpe)2D) was used to study the Deuterium Quadrupole Coupling Constant (DQCC) and the ionicity of the W-D bond (DQCC=34.1 kHz; ionicity 85%). 1 (W(Cmesityl)(dmpe)2H) shows several dynamic exchange processes in solution, such as HW/HW,(More)
The reaction of [Re(H)(NO)2(PR3)2] complexes (1 a: R = PCy3; 1 b: R = PiPr3) with [H(OEt2)2][BAr(F)4] ([BAr(F)4] = tetrakis{3,5-bis(trifluoromethyl)phenyl}borate) in benzene at room temperature gave the corresponding cations [Re(NO)2(PR3)2][BAr(F)4] (2 a and 2 b). The addition of phenyldiazomethane to benzene solutions of 2 a and 2 b afforded the moderately(More)