Karen W. Morse

Electronic transitions of aryl phosphines

Abstract Absorption and emission properties of Ph3P, MePh2P and Ph2P(CH2)nPPh2 (from n = 1 to n = 6) (Ph  phenyl; Me  methyl) are reported. The maximum absorption band at 250 - 260 nm has been assigned to a π → π* transition centered on the benzene ring. The lowest energy excited electronic state of the aryl phosphines has been assigned to an 1 → aπ transition associated with an obscured absorption band at about 300 nm. The lowest excited singlet and triplet state energies are calculated to be 79 - 82 kcal mol−1 and 75 - 77 kcal mol−1 respectively.

Predictive schemes for the reactivity of borane carbonyl and the stability of carbonyltrihydroborate anions, BH3C(O)X−

The reactivity of borane carbonyl (BH3CO) and its isoelectronic counterpart the acetylium cation (CH3CO+) are compared resulting in the formulation of (carbonyl)trihydroborate anions, BH3C(O)X−, which are isoelectronic and isostructural with organic carbonyls. By analogy with the ease of reduction of organic carbonyl compounds by hydroborate, the relative stability towards self-reduction-oxidation (hydride transfer from boron to carbonyl carbon) in BH3C(O)X− is proposed. The postulated order, with increasing stability is BH3C(O)Cl− < BH3C(O)H− < BH3C(O)R− < BH3C(O)OR− < BH3C(O)NR−2 < BH3C(O)O2−. Experimental results of this study together with known chemistry are shown to be consistent with the proposed order. Further, it is suggested that a similar predictive scheme may be applicable to the chemistry of the amine-carboxyboranes (boron analogues of α-amino acids) and their derivatives.

Hypolipidaemic activity in rodents of boron analogs of phosphonoacetates and cyanoborane adducts of dialkyl aminomethylphosphonates

Boron analogues of phosphonoacetates proved to be potent hypolipidaemic agents in rodents, lowering both serum cholesterol and triglyceride levels. (C2H5O)3PBH2COOCH3 proved to be the most effective agent in mice, lowering serum cholesterol 46% and serum triglycerides 54% after 16 days. (C2H5O)3PBH2COOH and Na+H+(C2H5O)2(-O)PBH2COO- caused greater than a 40% reduction in lipids. The cyanoborane adducts of aminomethylphosphonates were generally less effective; (C6H5O)2P(O)CH2NH2BH2CN was the most effective, lowering serum cholesterol 32% and serum triglycerides 43% after 16 days. The phosphonoacetates appeared to lower lipid concentrations by several mechanisms. First, they lowered the de novo synthesis of cholesterol and triglycerides in the liver. Second, they accelerated the excretion of lipids into the bile and faeces. Thirdly, they modulated LDL and HDL-cholesterol contents in a manner which suggests they reduced the deposition of lipids in peripheral tissues, and accelerated the movement of cholesterol from tissues (e.g. plaques) to the liver for excretion into the bile.

Photoreactions of tetrafluorodiphosphine with partially fluorinated ethenes

Abstract The photoreactions of tetrafluorodiphosphine with partially fluorinated ethenes have been observed to result in the formation of 1,2-bis(diflourophosphino) -1-fluoroethane, 1,2-bis(difluorophosphino)-1,1-difluoroethane, and 1,2-bis(difluorophosphino)-1,1,2-trifluoroethane. A rapidly diminishing yield of product results with increasing fluorination of the olefin.

[(MePh2P)3CuBH4]: a single M–H bridged tetrahydroborate

The single-hydrogen bridge attachment of BH4 to copper in [(MePh2P)3CuBH4] is the first reported linkage of that type of BH4 to copper.

CHARACTERIZATION AND PROPERTIES OF SOME DIALKYL-1-(N,N-DIALKYLAMINO)-ALKYLPHOSPHONATES AND THEIR HYDROCHLORIDE SALTS

Abstract Several new dialkyl-1-(N,N- dialkylamino)alkylphosphonates were synthesized1a as well as their hydrochloride salts. These compounds, along with two previously reported compounds, have been characterized by spectroscopic methods as well as elemental analysis. Spectral analysis indicates that the molecules assume an oriented posture in solution which can influence their reactivity. Additionally, the hydrochloride salts of the diethyl-1-(N,N-dimethylamino)alkylphosphonates have shown anti-viral activity.

EXCHANGE REACTIONS USING N-METHYLMORPHOLINE-BORANE DERIVATIVES

Abst rac t : A general procedure is described for the exchange reactions between N-methylmorpholine-borane derivatives and various organic bases involving a simple work-up to produce exchanged products. Thus, the procedure utilizes readily available, easy to handle aqueous as well as liquid amines in the exchange reactions with N-methylmorpholine-BH2X (X = COOH, COOMe, CONHEt) giving the corresponding amine-BH2X in good to excellent yields. The method also utilizes other organic bases such as phosphine, phosphite, and amino acid ester in the exchange reaction to obtain their borane derivatives.

Copper(I) phosphine hydroborate complexes: A study involving hydroborates containing a BO bond

Abstract A study was made of the reactions between chlorotris(methyldiphenylphosphine)copper(I) and several hydroborates containing a boron-oxygen bond. The new complex ((acetoxy)trihydroborato)tris(methyldiphenylphosphine)copper(I) (Ph2MeP)3CuH3B(O2CCH3) was isolated and characterized by analysis, IR, and NMR data. Analogous reaction conditions using HB(OR)3− anions did not give a BH containing product nor did several other anions of the general type HBR3−. The ability of the hydroborate to complex is related to the Lewis acidity of the respective borane attached to H−.