Hexadiene complexes with silver

Hexadiene complexes with gold, 12 348 with iron, 12 263, 264 with platinum, 12 319 with rhodium, 12 297-299 with silver, 12 340 Hexafluorides, structures, 27 106-108 Hexafluoroacetone, 30 223-312, 44 317-318 metal complexes, 30 279-298 of cobalt, 30 286-287 of gold, 30 295... 

Catalytic forms of copper, mercury and silver acetylides, supported on alumina, carbon or silica and used for polymerisation of alkanes, are relatively stable [3], In contact with acetylene, silver and mercury salts will also give explosive acetylides, the mercury derivatives being complex [4], Many of the metal acetylides react violently with oxidants. Impact sensitivities of the dry copper derivatives of acetylene, buten-3-yne and l,3-hexadien-5-yne were determined as 2.4, 2.4 and 4.0 kg m, respectively. The copper derivative of a polyacetylene mixture generated by low-temperature polymerisation of acetylene detonated under 1.2 kg m impact. Sensitivities were much lower for the moist compounds [5], Explosive copper and silver derivatives give non-explosive complexes with trimethyl-, tributyl- or triphenyl-phosphine [6], Formation of silver acetylide on silver-containing solders needs higher acetylene and ammonia concentrations than for formation of copper acetylide. Acetylides are always formed on brass and copper or on silver-containing solders in an atmosphere of acetylene derived from calcium carbide (and which contains traces of phosphine). Silver acetylide is a more efficient explosion initiator than copper acetylide [7],... 

Complex polyfunctional molecules can often be assembled efficiently by short, spectacular sequences of reactions, an example of which is the preparation of the pentasubstituted benzofuran 1. Thus, addition of l-lithio-l-methoxy-3-(trimethylsilyl)-l,2-hexadiene to 3,4-dimethoxycyclobut-3-ene-l,2-dione gave the expected keto alcohol in 70% yield. This alcohol was heated at reflux temperature in toluene for 4 hours to give a 2,3,5,6-tetrasubstituted hydroquinone in 90% yield. Oxidation of the hydroquinone with silver oxide and potassium carbonate in anhydrous benzene (90%) followed by reaction of the quinone thus obtained with TFA in methylene chloride at 0°C then at room temperature for two days gave 1 in 75% yield. 

L2 = hexadiene, nbd). Bis(2,2 -bipyridine)binaphtholate reacts with [(j -COE)2Rh]2 followed by hexadiene and then silver tetrafluoroborate or with [(/ -nbd)2Rh](BF4) to give cationic dinuclear 36 (L2 = hexadiene, nbd). With [(/ -cod)IrCl]2 this ligand produces neutral 37. Into this category falls the complex similar to 34 with L2 = nbd and polypyridine ligand h s(2,2 -bipyridine)calyx[4]arene (03IC3160). 

With AgC104, 1,5-hexadiene, 1,7-octadiene, and 1,9-decadiene form 3 2, 1 1, and 1 1 complexes, respectively (85a). The 1 1 complexes are considered (85a) to be coordination polymers while the 3 2 complex of 1,5-hexadiene has been shown (45a) to have chelated diene-silver ion entities connected through a bridging diene molecule to produce a distorted trigonal coordination about the metal. 

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