Physikalische Chemie 111, Technische Hochschule.D-61 Darmstadt, Petersenstr. 15 Clri~iirr.schc Bitidung Fesikihper / tii~rtiquiiclrii~~o/,.r.voiiiti~ / Lciilittigsi~rririlritr~ I) Mc~pit,/isdii, tit~i.rrre.soti~tr~JsCl 'ind ""Gal1' NQR frequencies are reported for MeGa;'CI, ( M e = Na. K, Rb, Gal) together with the 3'CI NQR frequencies for MeGa"'C1, (Me : Na. K, Rb, Cs, Gal). and the "Br and '"Br NQR frequencies for KAI,Br,. Most of the corresponding "CI and "Gali1 resonances in MeGa2C17 are reported too. With the exception of RbGaCI, and CsGaCI, all NQR investigations were done as a function of the temperat u re. The complexes MeGa2C17 show seven "CI and two ""Ga NQR lines each. From the "CCI NQR spectra it is concluded that the ion lGa2~'l7)'' has a bridged structure analogous to the ions (Me2X,)0 in KAI2Br7 and Te4(AI2CI,),. SLx of the 3sCI resonances are assigned to ci-ystallographically inequivalent terminal CI atoms. the seventh "CI resonance showing a low frequency shift is assigned to the bridging C1 atom. The charge distribution of the ion (Ga2CI,)' was estimated within the frame of the Townes-Dailey theory. The selfconsistency of the calculations is satisfactory.For two compounds. CsCl . .xGaCI, and RbCl j,GaCI,. investigated by NQR spectroscopy, no definite structural proposals are available up to now. Froin the "Br NQR spectrum of KA12Br, no assignment either to terminal Br atonis or to the bridging Br atom is possible. A small degree of ( p + d), character involving the terminal Al-Br bonds is considered a conceivable explanation. Froiii the "CI NQR spectra in KGaCI, and GaGaCI, polymorphism is found. The transformation to the high temperature phase in either complex is accompanied with a lowering of symmetry of the GaCI, tetrahedra and an increase of the crystal field splitting. This finding is in qualitative agreement with a decrease in volume on changing to the high temperature phase.Es Htirden die "CIund h9Ga111-NQR-Frequenzen von MeGa:"CI, (Me = Na. K, Rb, Gal), die "'CI-NQR-Frequenzen von MeGa"lC'I, (Me -Na, K, Rb, Cs, Gal). sowie die "'Br-und "Br-NQR-Frequenzen von KAI,Br, gemessen. Die korrespondierenden "CI-und "Ga-NQK-Frequenzen von MeGa:"CI, wurden soweit als moglich untersucht. Mit Ausnahme von RbGaC1, und CsGaCI, wurden die NQR-Frequenzen als Funktion dcr Temperatur studiert. Die Koniplexe MeGazC17 zeigen jeweils sieben "CIund zwei "Ga-NQR-Linien. Aufgrund der 3sCI-Spektren wird fur das Ion (Ga2CI,)'-' eine I3ruckenstruktur angenommen. Sechs der "CI-NQR-Linien werden den kristallographisch iniquivalenten terminalen CI-Atonien. die aiebte nach niedrigeren Frequenzen verschobene 35CI-NQR-Linie dem Brucken-CI-Atom zugeordnet. Mit Hilfe der Theorie von Townes und Dailey wurde die Ladungsverteilung im Ion (Ga,CI,)" bcrechnet. Sie ist im Rahmen des Niherungscharakters der Rechnungen selbstkonsistent.Die NQR-Spektren von CsCl . xGaCI, und RbCl . yGaCI, erlauben keine eindeutigen Riickschlusse auf ihre Struktur.Irn 1:inklang mit der bekannten Kristallstruktur yon KAI,Br, wurden sieben "Br-NQR-Fr...

Molecular compounds of the type L · MeX3 (L  benzophenones, benzoylchlorides, 4‐chlorophenol; MeX3  AlBr3, AlCl3, GaCl3) were studied by NQR and IR spectroscopy. Also, in two compounds of the type chlorophenoxy aluminumdibromide the halogen NQR was investigated. On the basis of the 35Cl and 81Br NQR experiments, benzoylchlorides appear to be weaker donors than benzophenones are. Yet, the shift of the carbonyl stretching frequency due to the formation of the complexes is less for benzophenones. In adducts of benzoylchlorides with AlCl3 the shift of the 35Cl NQR frequency (assigned to Cl linked to the carbonyl C atom), Δv(35Cl), and the shift of the CCl stretching frequency, Δṽ(CCl), were measured. A positive correlation of Δv(35Cl) with Δṽ(CCl) was found. On the basis of the 69Ga and 35Cl NQR frequencies measured for some molecular compounds L · GaCl3 the charge transfer was estimated with the aid of the Townes and Dailey Theory. A comparison with results obtained analogously for inorganic complexes incorporating GaCl3 is given. From the NQR experiments conclusions concerning the structure of the compounds investigated were drawn.

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