The Structure of the Cyclic Tetramer of Dimethylgallium Hydroxide¹

Abstract

Structure of Cyclic Tetramer of Dimethylgallium Hydroxide 3907 curvature in the log -log a plot. Thus it is not certain what deviation, if any, would occur at a 2: 60 and, if so, to what extent it deviates. The same argument can equally be applied to the [r)]-a plot. Therefore it is gratifying to find the good agreement between the experimental points (Fig. 3) and the extended theoretical values (broken lines), thus enabling one to use these extrapolated values with some confidence. The lower experimental values than the calculated ones in curve 3 were at least partly due to the significant experimental errors at high shearing stresses. Similar strikingly good agreement was also found between extrapolated theoretical values and experimental points for PBLG No. 416 in the previous publication2 even for a 20-fold extension of a (to 1200) (figure not shown here). Nevertheless, the possible uncertainty involved in the extrapolation as mentioned above could be very serious and should be used with reservation unless future experiments indicate otherwise.Note added in proof.-Professor J. J. Hermans has kindly pointed out that the viscosity at the capillary wall, , can be obtained by straightforward differentiation and represented as l/i, = (1 / tR3t3 )d( QA) /dr the symbols having the same meaning as those in eq. 1 and 2 (see also, J.

A quadruply bonded dimolybdenum compound containing a novel bridging and chelating hexadentate ligand

“…The formation of such an eight-membered (Ga-O)4 ring is not without precedent and indeed the structure of the tetramer [(CH3)?Ga(OH)14 is well documented (13). In the present scheme the formally Mo (11) (15,(16)(17)(18)(19)(20)(21)(22)(23)(24).…”

“…It is interesting to note that the Mo-0 bond to the [CH3Ga(N,C3H,)O]:-ligand is significantly shorter than that to the acetato group, the near planarity at O(1) suggesting the possibility of T-interactions with both the dimolybdenum systen1 and with the gallium atoms. In fact both Ga-0 distances (Ga-O( I) = 1.853 (2) and Ga-O(3) = 1.861 (2) A) are considerably shorter than the mean Ga-0 distance of 1 .960 , & reported for ((CH,)?Ga(OH)], ( 13). The Ga-N ( 1 .96 l(3) A), Ga-C (1.950(6) A), and all other bond lengths and angles are as expected.…”

Synthesis and Crystal and Molecular Structures of the N,N-Dimethylethanol-aminogallane and N,N-Dimethylethanolaminogallium Dimethyl Dimers

“…The mean Ga-0 distances for tetraform centrosymmetric molecules featuring a hedrally and octahedrally coordinated gallium system of three fused rings. The [MeN(CH2CH2-atoms are both 1.96 A (14)(15)(16). On the basis of O),GaH], dimers (I) have C2 symmetry while hybridization effects alone the equatorial bonds the present molecules both have crystallo-would be expected to be shorter and axial bonds graphically imposed i (Ci) symmetry.…”

Tetra-tert-Butyl-di-m-Hydroxo Digallium(III) and 1,12-Diaza-3,4:9,10-Dibenzo-5,8-Dioxo-cyclo-Pentadecane. Structure and Isomers of the Coordination Compound

“…10 Early on it was found that hydrolysis of trimethylgallium with water yields a cyclic dimethylgallium hydroxide tetramer, [Me 2 Ga(µ-OH)] 4 , in the solid phase [13,14]. There has been some discussion of whether the tetramer or smaller oligomers are predominant in equilibrium dominated solutions as this question is only answered by very precise measurements [15,16].…”