Phosphorus and Gallium

The limited number of P-Ga compounds so far studied include some analogues of cf-cr and boraphosphines above. 

Compounds (9.154) contain approximately planar rings of Ga and pyramidal P atoms, but measured bond parameters are rather long and leave doubt about the existence of Jt-bonding within these rings [1-7]. 

The compound CsgGa2P4 is a salt which contains the anion GajPi (9.156a), and BagGa2P6 con tains the anion GajPg (9.156b) [8,9]. 

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Properties Pale-orange, transparent crystals or whiskers up to 2 cm long, made by vapor phase reaction at relatively low temperatures between phosphorus and gallium suboxide. These crystals are intermediate between normal semiconductors and insulators or phosphors. They operate over a temperature range of —55 to 500C. Gallium phosphide is electroluminescent in visible light. 

Figure 16.4 Projections of two related fluorogallophosphate structures (left) Mu-5 and (right) DMAP-GaPO with the d4r-F and side opened d4r-F units, respectively (oxygen atoms of the inorganic framework have been omitted for clarity). White, light and dark grey spheres represent fluorine, phosphorus and gallium, respectively...

Metal-Phosphorus Bono Lengths, Torsion Angles between the Metal and Phosphorus Coordination Planes, Sums of Angles at Phosphorus, and 3IP NMR Chemical Shifts for Three-Coordinate Aluminum, Gallium, and Indium Phosphides... 

The deshielded 31P and 13C NMR chemical shifts observed for 41-43 ( 31P +130, 13C +76, /PC 85 Hz) are consistent with the presence of a P = C double bond and positive charge development at phosphorus these spectroscopic data are in fact very similar to those observed for the methylenephosphonium salt 40.59,6° This similarity is reinforced by the X-ray analysis of the gallium adduct 42 (Fig. 4) (i) The phosphorus and carbon atoms adopt a trigonal planar geometry, (ii) there is a twist angle between the two planes of 34.1°, and (iii) the phosphorus-carbon bond distance is rather short (1.61 A). 

Addition of aluminium and gallium trichloride to phosphorus ylides 96a-96c leads to the formation of the heterocyclic salts 97a-97c (Scheme 34). 

After Gallium, Ga, the next known element in order of RAM was arsenic (As). But arsenic is nothing like carbon and silicon in its properties. It is, on the other hand, a lot like nitrogen and phosphorus. So the second difference between Mendeleev and Newlands is that Mendeleev put arsenic under nitrogen and phosphorus and left a gap under carbon and silicon. 

The dilFerence in these reorganization energies cannot wholly account for the variation of /-- 12kcal in the heats of addition reactions. This variation must be, in part, due to a weaker o-bond between phosphorus and boron atoms than between nitrogen and boron atoms. This can be shown from the heats of addition reactions between gallium trimethyl and either trimethylamine or tri-methyl pho sphine. These heats are shown in Table 7, together with similar data for indium trimethyl. 

THE BRILLIANT COLORS OF light-emitting diodes (LEDs) arise from the composition of the materials from which they are made. The LEDs shown here are compounds of gallium and aluminum mixed with nitrogen, phosphorus, and arsenic. GaN, GaP, and GaAs can make solid solutions with each other and with AIN,... 

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