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Herein we report the syntheses and characterization of the novel title mono- and dinuclear compounds from pentacarbonyliron. They were obtained in a stepwise manner by UV irradiation of [Fe(CO)5] with the appropriate ligand in THF and were characterized by ¹H, 13C, 13C{¹H} 31P and 31P{¹H} NMR spectroscopy, by IR spectroscopy and by elemental analysis. The single crystal X-ray molecular structure of [Fe(CO)4(DABCO)] is described. The 13C{¹H} NMR spectra of each of the title complexes reveal their fluxional behavior, which presumably occurs via Berry pseudorotation.

Several experimental, as well as theoretical studies are conducted to explain the steric stabilization of a monomeric proalumatrane (AIL) complex. The results show that the coordination of a water molecule to the tetracordinate aluminum in AIL leads to very high stabilization energy.

The synthesis and structural characterization of a new generation of bulky electron-rich phosphines of type [R'.sub.2]PN=P[([i.sub.B]uNC[H.sub.2]C[H.sub.2]).sub.3]N, (R'= Ph, Pr, Bu) where in the pro-azaphosphatrane unit is one of the three bulky electron-rich substituents is reported. The Pd[(OAc).sub.2]/BU catalyst system was particularly efficient for the coupling of arylboronic acids with aryl bromides as well as aryl chlorides to give biaryls in excellent yields.

Proazaphosphatrane ligands in combination with Pd2(dba)3 generate highly active catalysts for Buchwald-Hartwig amination of aryl chlorides. Either a 1:1 or 2:1 ratio of ligand to Pd was found to be effective.

Factors influencing the formation of the phosphazides or iminophosphoranes in the reaction of 1,3,5-cis-traizidocyclohexane with the electron rich tris(dialkylamino)phosphines P(NMe2)3 and N(CH2CH2NMe)3P in acetronitrile for 3 h is discussed. Findings show that the presence of electron-rich sterically crowded phosphorus in compounds of type 3b promotes protonation of nitrogen in the azido group, thus facilitating departure of [6bH](super +), benzene formation, and dinitrogen evolution.

Conditions for an efficient ligand-, copper-, and amine-free palladium-catalyzed Sonogashira reaction of aryl iodides and bromides with terminal alkynes are developed. The important features of this method are the use for tetrabutylammonium as the base and room temperature conditions and the tolerance of a broad range of functional groups in both reaction partners.

Research has been conducted on the atrane-like six-coordinate (RO) (sub)2 TaL, where R=Me or Et and L= tris(2-oxy-3,5-dimethylbenzyl)amine, complexes with three six-membered rings. The synthesis and characterization of these complexes have been carried out and the details are presented.

Research has been conducted on the Michael addition reaction. The results of the 1,4-addition of alpha-amino ester's higher nitroalkanes, primary alcohols and a Schiff base to alpha,beta-unsaturated substrates are reported.

Research has been conducted on the activated allylic compounds. The results of the proazaphosphatrane-catalyzed reaction of these compounds carried out to produce a Baylis-Hillman or a beta,gamma-unsaturated 1,2-addition products are discussed.

Research has been conducted on P(CH (sub)3 NCH (sub)2 CH (sub)2) (sub)3 N reactivity. The mechanism of action of this compound has been investigated and the results are presented.

Research has been conducted on the semi-stabilized ylide prepared from nonionic base P(MeNCH (sub)2 CH (sub)2) (sub)3 N. The reaction of this ylide with aldehydes has been carried out to produce alkenes with quantitative E selectivity and the results are discussed.

P(MeNCH2CH2)(sub 3)N unlike its acyclic analogue P(NMe2)(sub 3) was found to be a highly selective reagent providing epoxides from aryl aldehydes with trns/cis ratios as high as 99/1. The phosphorus atom in P(MeNCH2CH2)(sub 3)N seemed to be more nucleophilic than that in P(NMe2)(sub 3) to produce faster reactions.

Results demonstrate that the tert-Butyldimethylsilyl protective group is efficiently removed from tert-Butyldimethylsilyl-OR ethers using a nonionic base by catalysis. The mechanism of desilylation reactions are discussed.

Research has been conducted on the C (sub)3 chiral alpha-phenylethylamino trisaminoamine synthesis. The use of (super)1 H NMR spectroscopy in determining the enantiomeric ratios of chiral azides is discussed.

Research has been conducted on the catalysis of the primary alcohol acylation with enol esters. Results demonstrate that acetals and epoxides survive under the reaction conditions.

NaH can deprotonate vicinal dibromides and tricyclic azaphosphatranes can be used as catalysts in the dehydrohalogenations of the bromides. NaH is not as effective as other bases such as DBN, DBU or KO-t-Bu but it is cheaper. Making the NaH and the procatalyst and catalyst insoluble leads to the easy isolation of spectroscopically pure products by filtration of the reaction mixture followed by evaporation. The procatalyst can be recovered easily by washing and drying the filter cake.

The application of catalytic amounts of the proazaphosphatranes P(meNCH2CH2)3N, P(i-PrNCH2CH2)3N and P(HNCH2CH2)(i-PrNCH2)2N as nonionic bases in the reaction of nitroalkanes with carbonyl compounds is described. The reaction occurs at room temperature with 2.2 equiv of magnesium sulfate to obtain the corresponding beta-nitroalkanols in excellent yields. Aldehydes react quantitatively in 5-60 min, while ketones need up to 3 h to react with nitromehane and up to 7 h for the reaction of ketones with higher nitroalkanes.

Students can sketch pictures of molecular orbitals (MOs) for a wide variety of organic, organometallic, metal complex and cluster molecules that have a large variation in structure. Each MO, that is, linear combination of atomic orbitals (LCAO), reflects symmetry of an atomic orbital shown as a pattern-making device at the center of the molecule. That is the core of the concept. Knowing the shapes of atomic orbitals enables a student to put together a pictorial representation of all linear combinations of atomic orbitals in a set of MOs.

A study is conducted on the role of transannulation in the basicity of the bridgehead nitrogen and phosphoryl oxygen of O=P(MeNCH2Ch2)2N in the presence of different receptors. The compound reacts with phosphoryl and silyl chlorides to yield the isolable salts (ZOP(MeNCH2CH2)3N)Cl where Z = Ph2P(O), PhP(O)Cl, 1/2PhP(O), MeSiCl2 and SiCl3. Reactions involving the acyclic analog of the compound, O=P(NMe2)3 are also discussed.

A study was conducted to describe the use of a novel class of nonionic Lewis bases for the direct catalytic synthesis of a number of functionalized alpha,beta-unsaturated nitriles from aldehydes and acetonitrile. The efficiency and scope of the experimental approach were evaluated based on the condensation and dehydration of benzyl cyanide. Results indicated that aliphatic aldehydes do not correlate with acetonitrile to generate alpha,beta-unsaturated nitriles.

The chiral (4S-(+)-3-(isocyanoacetyl)-4-(phenylmethyl)-2-oxazolidinone) (R)-1 and its (S)-1 enantiomer were synthesized from chiral auxiliary-bearing isocyanide enolates. The synthetic process is characterized by the formation of (S)-4 from [(S)-7]ClO4 by the conversion of the (CO)-O to (CO)-O-N bonds during the neutralization of the ammonium group. Furthermore, the synthetic process is also characterized by the transformation of the formamide group to an isocyano group 2 during the formation of (R)-1 and (S)-1 from (R)-8 and (S)-8.

A novel method of synthesizing non-ionic superbase-catalyzed silylation of alcohols was described through the utilization of silylation reagent, tert-butyldimethylsilylchloride (TBDMSCI). The approach involved the TBDMSCI reagent and the catalyst, P(MeNCH2CH2)3N. The advantages of using this approach lies in the fact that yields of the silylated alcohols and phenols are high, the catalyst can be recycled and can catalyze various reactions.

New azastannatranes have been synthesized and their chemistry is ruled by the way the tricyclic atrane framework is preserved. New six-coordinate tin compounds have been produced. The tricyclic atrane framework shows preservation when there are substoichiometric quantities of water. A new fluorotin salt results from hydrolysis, and X-ray analysis shows that its structure includes a six-coordinate tin atom. The six-coordinate nature is shown by NMR and IR spectra.

Synthesis for 4S-(+)-3-(isocyanoacetyl)-4-(phenylmethyl)-2-oxazolidinone (R)-1 and (S)-1 indicated possible synthon applications for both chiral auxiliary-bearing isocyanides in asymmetric synthesis. Synthesis of (R)-1 and its enantiomer (S)-1 also yielded the optically active fluorescence system (R)-2 and (S)-2, their related quantum yields and (S)-2's crystal structure.

1-Oxo-2-oxa-1-phosphabicyclo(2.2.2)octane was synthesized in a multistep sequence starting from hypophosphorous acid. A rate enhancement is observed in strong base, with the bicyclic phosphinate 1-oxo-2-oxa-1-phosphabicyclo(2.2.2)octane hydrolyzing two orders of magnitude faster than the bicyclic phosphate OP(OCH2)3CCH3. Acceleration is entirely enthalpic. The greater ease with which OP(OCH2)3CCH3 achieves the five-coordinate transition state is credited for the rate enhancement. The molecular structure of 1-oxo-2-oxa-1-phosphabicyclo(2.2.2)octane, compared with OP(OCH2)3CCH3, shows no signs of strain within either bicyclic framework.

A powerful nonionic Lewis acid superbase 1a is an efficient acylation catalyst of benzyl alcohol and gives an insoluble benzoylation byproduct that permits the regeneration of 1a in a one-step process. Comparison of the benzoylation rates of (plus or minus)-menthol in C6D6 indicates that acetylation and benzoylation with 1a are enhanced in CH3CN and C6H6, respectively. Superbase 1a also yields a P-acylation intermediate which is thermodynamically more stable.

Metathesis reactions were used to prepare new volatile (dialkylamino)azametallatranes of group 4 metals in various amounts. Single-crystal x-ray diffraction studies were used to examine the syntheses and characterization of the volatile precursors and crystal structures of the metals. Results showed that two compounds exhibit a distorted trigonal bipyramidal metal center. The crystal data for all the compounds produced are presented.

The transamination of Ti(NMe2)4 with the disubstituted tren ligand (i-PrNHCH2CH2)2NCH2CH2HN2 generates azatitanatrane Ti(i-PrNCH2CH2)2NCH2CH2N 2 (13) in 44% yield. The dimeric structure of 13 is rigid in solution as obtained from the NMR time scale. Short axial Ti-N bonds are present in the azatitanatrane Me2NTi(MeNCH2CH2)3N.

The synthesis and characterization of the compounds [Li3(Me3SiNCH2CH2)(sub 3) N(THF)(sub 2)] and {(mu cubed-Cl)Li3H4[(Me3SiNCH2CH2)(sub 3)N](sub 2)} by 1H, 13C, 29Si, and 7Li NMR spectroscopies, and their structure is determined by single crystal X-ray crystallization. [Li3(Me3SiNCH2CH2)(sub 3) N(THF)(sub 2)] contains a trigonal monopyramidal lithium center while {(mu cubed-Cl)Li3H4[(Me3SiNCH2CH2)(sub 3)N](sub 2)} uses a LiCl to link two amido triamine ligands together. Results on NMR analysis are discussed.

Nucleophilic substitution reactions of ClSi(R'-NCH2CH2)3N with amide anions help synthesize aminoazosilatranes of the type R2NSi(R'NCH2CH2)3N. The reaction mechanisms are affected by the equatorial NR' functionalities and are accompanied by hydride and fluoride transfer reactions, with the nucleophile being substituted at the pentacoordinate silicon. The formation of reaction products is influenced by stereoelectronic factors, the nature of nucleophilic reagents and reaction conditions.

A nonionic superbase P(MeNCH2CH2)3N catalyzes the reaction of isocyanoacetates with acyl chlorides or acid anhydrides producing oxazoles, which react with HCl-MeOh to generate alpha-C-acyl amino acid esters. The superbase catalyzes the reaction of nitroalkene with isocyanoacetates producing pyrroles, which help synthesize porphyrins. Strong basicity and nucleophilicity of the superbase make the base as an efficient nonionic deprotonating agent, and the deprotonation occurs even at low temperatures.

New synthetic methodologies enable the preparation of monomeric and dimeric azatranes. X-ray diffraction studies show that the dimeric azagallatrane and azaalumatranes have an unusual cis configuration of the substituents on the four-membered central (M-N)2 ring. When the substituted alkyl group is bulky, the azagallatrane is monomeric, and is dimeric when the alkyl group is methyl. Nitrogen atoms coordinate with the Al and Ga atoms of the azatranes to yield a distorted trigonal bipyramidal geometry.

Reaction between (Al(NMe2)3)2 and (tert-BuMe2SiNHCH2CH2)3N produces a new monomeric azaaluminatrane. Multinuclear NMR, IR and mass spectroscopic studies help characterize the monomeric azaaluminatrane. Analogue of this azaaluminatrane has a trigonal monopyramidal aluminum center. X-ray structural studies of a dimeric azaaluminatrane show that it has a Cis-configuration of the central four-membered ring. The Al atom exhibits a distorted trigonal bipyramidal sphere. NMR studies show that shielding increases with increase in coordination number.

ZP(MeNCH2CH2)3N, where Z is a lone pair, catalyzes the trimerization of isocyanates to form perhydro-1,3,5-triazine-2,4,6-triones at low concentrations of 0.0033 mol%. Analysis of the catalyst's lifetime reveals that it can be reused at least six times without degradation. Two other compounds Ch double bond P(MeNCH2CH2)3N, (Ch is O, S), are better catalyst for the conversion of isocyanates to carbodiimides than their acyclic analogues. Structural studies show that the P-N(ax) transannulation influences catalytic properties.

Perchlorate salts of H(TEA)(super +), Li(TEA)(super +) and Na(TEA)(super +), where TEA is triethanolamine, are synthesized. X-ray crystallography is employed to analyze the structures of the H, Na and Ba complexes. Introduction of a positive ion separates the TEA moieties of the cage-like dimers partially in Ba and completely in H. The Na(super +) complex has metal bridging by OH oxygens. ClO4(super -) is a monodentate ligand to the Na(super +) in the Na complex and a bidentate ligand to two Ba(super 2+) ions in the Ba complex.

The reaction of Me2NSn(NMeCH2CH2)3N, an azastannatrane, with protolytic reagents and the formation of the azastannatrane by treating Me2N with protic reagents are described. Spectroscopic studies of the azastannatrane reveal an absorption band at 300 cm (super -1) due to the association of vibration mode and Sn-N bond coordinates. Recemization barriers of azastannatrane are low.

Eight azastannatranes with the general formulae XSn(MeNCH2CH2)3N and ZSn(HNCH2CH2)3N, where X = Me, n-Bu, Ph, Me2N or 1/2O and Z = Me, Ph or n-Bu, are produced and characterized. X-ray crystallography and NMR studies reveal pentacoordinated bond in these complexes. Infrared and mass spectral features and racemization values are also determined.

Tetradentate amine moiety (MeNCH2CH2)3N was found in imidovanadium amides. A high quantity of RN = V(NMeCH2CH2)3N was synthesized by the easy transmetalation reaction between azastannatranes and N-replaced tris(siloxy)vanadium(V)imides. FT-IR, high-resolution mass and liquid and solid state heteronuclear NMR spectroscopy were used to define the properties of the compounds. The carbon nucleus was quadrupolarly-coupled with vanadium in the CP/MAS C NMR spectrums of the compound.