ZUSAMMENFASSUNG:Verschiedene Methoden zur Radikal-Polymerisation von Acrylamid mit und ohne Losungsmittel werden beschrieben. Die durch y-Strahlen ausgeloste Polymerisation ergibt sehr hochmolekulare Polymerisate; dagegen haben die mittels Fenton-Reagens erhaltenen Produkte nur sehr geringe spezifische Viskositlt. Ultraschall wirkt auf das Monomere polymerisierend und auf das Polymere depolymerisierend. Aus den Viskositatskurven eines reinen Polymerisates und seiner Fraktionen ist zu schlieRen, d d solche Polyacrylamide in waoriger Losung als homoopolare Molekiikolloide vorliegen. SUMMARY:cr lamide in solution and in bulk are described. The y-rays iudueed p o l y m~r~~i~~~a b 6 j Y o a u e t s of extremely high molecular weight. The polymerization induced by Fenton's Reagent on the other hand leads to products of low intrinsic viscosity. Ultrasonic waves polymerize the monomer and depolymerize the polymer. The viscosity of a pure polymer and its fractions plotted against the concentration shows that these polyacrylamides in aqueous solution are

GeI2 reacts with [M2(CO)10]2– (M = Cr, W) leading to reductive coupling of two GeI2 units to produce the [Ge2I4]2– ligands of [{(OC)5M}I2Ge–GeI2{M(CO)5}]2– (1a and 2a). The [Ph4P] salts of these anions have been characterised by X‐ray structure analyses as have the [Ph4P] salts of [{(OC)5M}Cl2Ge–GeCl2{M(CO)5}]2– (1b and 2b) obtained from the iodo derivatives 1a and 2a by halide metathesis with [Ph4P]Cl. Treatment of GeI2 with [W2(CO)10]2– in the presence of 2,2′‐bipyridine leads to [{(OC)5W}I2Ge–Ge(bipy){W(CO)5}] (3). The digermanium ligands in 1–3 contain germanium in the unconventional formal oxidation state +I. Reductive condensation of [{(OC)5Cr}I2Ge–GeI2{Cr(CO)5}]2– (1a) by addition of [Cr2(CO)10]2– leads to the octahedral cluster [{(OC)5Cr}6Ge6]2– (4) in a yield of 40%. The sequence of reactions as reported describes the first systematic approach to the synthesis of [E6]2– clusters.

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