New approach to immobilization of coal-model compounds on silica using a calcium carboxylate linkage

In an earlier report, the authors described efforts to study the hydrothermolysis of surface-immobilized coal model compounds by attaching 1-(4{prime}-hydroxyphenyl)-2-phenylethane to the surface of fumed silica via a Si-OAr linkage using procedures developed by Buchanan, Poutsma and coworkers and heating the resultant material (SiO-DPE) under D{sub 2} pressure. Despite the successes noted here, they sought to find a method for constructing links between silica and organic materials which might better survive hydroliquefaction conditions. Attachment of long-chain aliphatic carboxylic acids to silica through Mg{sup ++} or Ca{sup ++} ions is a patented method for silica flotation which they thought might be adapted to their purposes. This preprint is a preliminary report on the preparation, thermolysis and hydrothermolysis of materials believed to have the general structure, SiO{sup {minus}}Ca{sup ++}{sup {minus}}O{sub 2}CAr