Atranes

The PMR spectra of acidified solutions of metalloatrane-3,7,10-trione dihydrates containing a group-IIIB metal atom (M=Al, Ga, In, Tl) in D₂O were studied. The equivalence of the three atrane half-rings in all of the investigated molecules and of the methylene protons in each half-ring was proved. Spin-spin coupling of²⁰³Tl and²⁰⁵Tl with protons, which is apparently realized through a TlN transannular coordinate bond, is observed in the PMR spectrum of thallatrane-3,7,10-trione (M=Tl). The factors that determine the magnitudes of the chemical shifts of the methylene protons are discussed.See [1] for communication XXXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 312–314, March, 1973.     

Atranes

Silatrane, in the presence of the corresponding sodium alkoxide of phenoxide readily reacts with alcohols and phenols with the liberation of hydrogen and the formation of 1-alkoxy- or 1-aryloxyatranes, . Depending on the nature of the alcohol or phenol, the rate of the reaction falls in the following sequence: p-CH₃OC₆H₄OH > p-(CH₃)₃CC₆H₄OH = n-C₄H₉OH = = n-C₅H₁₁OH > i-C₄H₉OH > s-C₄H₉OH > p-CH₃C₆H₄OH > C₆H₅OH > > p-ClC₆H₄OH > t-C₄H₉OH > p-O₂NC₆H₄OH > C₆F₅OH. The rate of the dehydrocondensation reaction of hydrosilanes with alcohols rises in the sequence . In the presence of ZnCl₂ as catalyst, the dehydrocondensation reaction of silatrane with alcohols takes place considerably more slowly and does not go to completion. The formation of 1-organyloxysilatranes from silatrane and alcohols does not take place in the presence of H₂PtCl₆ or in the absence of catalysts. Using the dehydrocondensation reaction, twelve 1-organyloxysilatranes have been synthesized, two of which were previously unknown.     

Atranes

The infrared absorption spectra over the range 400–1700 cm^–1 of ten organyl- and organoxysilatranes, p-CH₃C₆H₄O] are investigated. The SiN coordinate link in these compounds is largely unreflected in the fundamental vibration frequencies of the bonds of the central silicon atom or the internal vibration frequencies of the substituents X linked to that atom. However, all the IR spectra have an absorption band in the 570 cm^–1 region, related to the valence vibrations (SiN), or manifesting itself as the frequency (Si-O) of the XSi (O)₃ group, substantially lowered because of interaction between the Si-O and Si-N bonds. Evidence in favor of this bond is shift of the (Si-H) frequency in the spectrum of silatrane(X=H).For Part V see [1].     

Atranes

The conformational energy of the 1-methylsilatrane molecule for sp³ and sp³d hybridization of the silicon atom was calculated. The known data on the structure of the atrane portion of the molecule are in good agreement with the results of the calculation for sp³d hybridization and differ radically from the results of the calculation for sp³ hybridization of the silicon atom. The conformational factors constitute a considerable contribution (11.4 kcal/mole) to the forced change in the hybridization of the silicon atom. An analysis of the dependence of the energy of the 1-methylsilatrane molecule on the distance between the Si and N atoms shows that a stable exo form, isolated to any extent by a considerable conformational barrier from the real structure with an SiN transannular interaction, does not exist.See [1] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 5, pp. 613–617, May, 1974.     

Atranes

Methods for the preparation of bis(1-silatranyloxy)alkanes, - , where R=-(CH₂)_n-(n=2–6), -CH₂CH(CH₃)-, and-CH₂CH₂OCH₂CH₂-,were developed on the basis of reactions of alkanediols with 1-hydro- and 1-ethoxysilatrane. In the presence of excess alkanediol these reactions give less stable 1-(hydroxyalkoxy)silatranes, , that are difficult to isolate.     

Atranes

Magnetic susceptibilities and dipole moments of 1-oxovanadatranes are measured, and their IR spectra investigated. The results obtained show these compounds to contain a transannular dative VN bond.For Part VIII see [19].     

Atranes

The hydrolysis of silatranes of the : type (R=alkyl, aryl) in the presence of HCl at 25°C is described by a second-order kinetic equation. The correlation dependence of the log k values on the σ _OR ^* values makes it possible to divide the investigated compounds into two reaction series — 1-alkoxy- and 1-aryloxysilatranes. An investigation of the potentiometric curves and the change in the acid functions of the media during the hydrolysis of the silatranes made it possible to propose a scheme for the mechanism of this reaction. The linear dependence of the v values on [HCl] provides evidence that noncatylic hydrolysis of the silatranes practically does not occur under the investigated conditions. A salt effect is not manifested during the hydrolysis of the silatranes (at KCl concentrations from 0.05 to 0.25 mole/liter). The toxicity of the 1-aryloxysilatranes is basically reduced as their rate of hydrolytic cleavage increases.     

Atranes

Methods of synthesizing hitherto unknown 1-hydroxy-1-oxomolybdatranes, are developed. They are based on the reactions of trialkano lamines with molybdenum trioxide, meta- or orthomolybdic acids, or ammonium molybdate. Four compounds of this kind are characterized,, and its 3-methyl, 3, 7-dimethyl, and 3,7,10-trimethyl derivatives.For Part XI see [1].     

Atranes

A method has been developed for the synthesis of the previously unknown 1-organylgermatranes\({\text{RG}}\) (R is alkyl or aryl). It is based on the cleavage of the polymeric products of the hydrolysis of organyltrihalogermanes with triethanolamine in the presence of an alkali-metal hydroxide. Four 1-organylgermatranes have been obtained by this method and characterized. The parameters of the elementary cells of the crystals of these compounds have been determined by X-ray structural analysis.     

Atranes

Methods were developed for the synthesis of ferratrane, the previously unknown cobatrane, and their derivatives. The methods are based on the reactions of Fe(OH)₃· Fe(OC₂H₅)₃ and CoO(OH) with tris(2-hydroxyalkyl)amines.See [1] for communication XXIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1172–1173, September, 1972.     

Atranes

The UV absorption spectra in the 1800–2400 Å region of 1-alkylsilatranes and 1-alkylgermatranes have been studied, confirming the presence of SiN and GeN bonds, respectively, in these compounds.For part XIX, see [1].     

Atranes

Complexes of ferratrane-3,7,10-trione (I) of the composition I · H₂O, I · H₂O₂, I · OS(CH₃)₂, and I · 2OS(CH₃)₂ were synthesized. The IR spectra and derivatograms of these compounds were studied.See [1] for communication XXXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 164–170, February, 1973.     

Atranes

The UV absorption spectra in the 1800–2400 Å region of 1-alkylsilatranes and 1-alkylgermatranes have been studied, confirming the presence of Si←N and Ge←N bonds, respectively, in these compounds.     

Atranes

The kinetics of the hydrolysis of 1-(-chloroalkyl)silatranes (where R=ClCH₂ Cl₂CH, and CH₃ClCH, and n=1–3) at 25°C in neutral and acidic aqueous and aqueous alcoholic media with H₂O,²H₂O, and H₂ ¹⁸O were studied. The rate of hydrolysis in acidic media is considerably higher than in neutral media. The introduction of methyl groups in the 3, 7, and 10 position of the atrane ring and an increase in the electronegativity of the substituent attached to the silicon atom lower the rate of hydrolysis. According to the mass spectrometric data, the triethanolamine formed during hydrolysis in H₂ ¹⁸O does not contain¹⁸O, which indicates hydrolytic cleavage of the Si-O bond rather than the O-C bond.See [1] for communication LXVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1344–1346, October, 1976.     

Atranes

Genetal methods are described for the preparation of metalloatrane-3,7,10-triones, containing an atom of a ter-, quarter-, or quinquevalent metal (mainly in the form of hydrates). Seven intramolecular compounds of this type (with M = Nd^III, ClTi^IV, ClZr^IV, Ce^III, HOPb^IV, HOMn^IV, HOOU^VI), have been prepared, of which only two (with M = Nd^III and HOOU^VI) were known previously. Compounds with the composition N (CH₂COO)₃M · mN (CH₂COO)₃ · nH₂O with M = Nd^III, Th^IV, CO^III and Ni^III (m=1) and with M = Sb (m=3 and 4) have also been obtained.For part XVIII, see [1].     

Atranes

The dipole moments of the Si(OCH₂CH₂)₃N heterocyclic framework were calculated within the framework of an additive scheme by means of data from x-ray diffraction and conformational analysis of silatranes. The direction of the dipole moment of this fragment coincides with the “experimentally” determined value (from nitrogen to silicon), and its magnitude is ～3 D. The dipole moment of the Si ← N coordinate bond was estimated to be 2.2 D, which corresponds to charge transfer from the nitrogen atom to the silicon atom (to the extent of 0.2 e). These results refute the existing concepts of the exceptionally high polarity of the transannular Si ← N bond in silatranes.     

Atranes

A method of synthesizing hitherto unknown 1-aroxysilatranes (R=aryl) is worked out. It is based on transesterification of lower tetraalkoxysilanes with an equimolecular mixture of triethanolamine and the appropriate phenol (naphthol). Using the method, 12 compounds of the indicated type have been prepared and characterized, the yields in the main exceeding 90%.For Part VII see [1].     

Atranes

The structures of 1-substituted silatranes and germatranes (M = Si, Ge)] are discussed on the basis of data from x-ray diffraction analysis and other physicochemical methods. The found values of the interatomic distances and valence angles in molecules of these compounds directly prove the existence of a transannular NM coordinate bond and confirm the correctness of the previously proposed geometrical model of a molecule with a trigonal-bipyramidal orientation of the valence bonds of the central atom M. In metalloatranes (M = Si, Ge, B), the distance from the nitrogen atom to the plane in which the three oxygen atoms lie is a constant value (2.00±0.05 Å). The effect of substituent X on the structure of the molecule was established.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 617–623, May, 1973.See [1] for communication XXXIII.