Synthesis, 119Sn, 13C and 195Pt NMR studies of five-coordinate rhodium(I), iridium(I) and platinum(II) complexes containing three trichlorostannate ligands

The synthesis and ¹¹⁹Sn NMR characteristics of new five-coordinate tris(trichlorostannato) complexes of Rh^I, Ir^I and Pt^II are reported. The Rh^I and Ir^I complexes are complex dianions of the form (PPN)₂[M(SnCl₃)₃L₂] where L can be CO, CN (cyclohexyl) or L₂, a diolefin such as 1,5-COD or NBD (norbornadiene). The anionic platinum complexes (PPN)[Pt(SnCl₃)₃L₂] contain similar L ligands. A number of neutral monotrichlorostannato complexes of type [M(SnCl₃)L₄] including [Ir(SnCl₃)(NBD)(1,5-COD)] have been prepared and characterized. Their δ(¹¹⁹Sn), δ(¹³C), δ(¹⁹⁵Pt) as well as ¹J(¹⁰³Rh, ¹¹⁹Sn), ¹J(¹⁹⁵Pt, ¹¹⁹Sn), ²J(¹¹⁹Sn, ¹¹⁷Sn) and ²J(¹¹⁹Sn, ¹³C) data are given. A trans influence series, based on ¹J(¹⁹⁵Pt, ¹¹⁹Sn), reveals the following sequence: H^? > PR₃ > AsR₃ > SnCl₃^? > olefin > Cl^?.     

The preparation and 119Sn and 19F NMR spectra of some trifluoromethylphenyltin(IV) compounds

The preparation of a series of new trifluoromethylphenyltin(IV) compounds, Bu_nSn(C₆H₄CF₃-3)_4-n, (C₆H₄CF₃-3)SnCl₃, (C₆H₄CF₃-2)SnCl₃, and some related adducts with 2,2¹-bipyridyl and 1,10-phenanthroline, is described. ¹¹⁹Sn and ¹⁹F chemical shifts have been determined, together with values of J(¹¹⁹Sn=F) and ³J(¹¹⁹Sn=H_itortho), and the possibility of a “through space” tinfluorine coupling mechanism is also discussed.     

Carbon-13 NMR studies of some organotin(IV) compounds

The ¹³C chemical shifts and ¹³C−¹¹⁹Sn, ¹¹⁷Sn coupling constants for several organotin(IV) compounds R_xSnCl_4−x (R = Me, Buⁿ, Ph; x = 1−4) have been measured in both inert (CDCl₃) and donor (DMSO-d₆) solvents, as have ¹³C data for the compounds R_xSnR′_4−x (R = Me, Ph; R′ = Buⁿ and R = Me; R′ = Ph; x = 1−3) and the compounds Me₃SnX (X = pseudo halide). The δ and ¹J(C-Sn) values appear to depend mainly on the type and number of substituents on tin and the donor ability of the solvent. There are linear relationships between the number of substituents (x) and both δ and ¹J(C-¹¹⁹Sn) for almost the R_xSnX_4−x series (R = Me, Buⁿ, Ph; X = Cl and R = Me, Buⁿ; X = Ph; x = 1−4), when measured in a single solvent, e.g. CDCl₃. There is an excellent linear relationship between ¹J(C-¹¹⁹Sn) and ²J(¹HC-¹¹⁹Sn) for the compounds Me_xSnCl_4−x. Determination of ¹³C data for Me₃SnCl and Ph₃SnCl in a range of solvents reveals that the value of ¹J(C-Sn) increases with the donor ability of the solvent.The marked increase in the values of ¹J(C-¹¹⁹Sn) in DMSO-d₆ for the compounds R_xSnCl_4−x(R = Me, Buⁿ,Ph) on going progressively from x = 4 to x = suggest tin coordination numbers of 4, 5, 6 and 6, respectively. Some additional physical data are presented for the isolated complexes from DMSO and the compounds Ph_xSnCl_4−x(x = 1−3) and Me₃SnX with X = N₃ or OCOMe.     

Stereochimie de la stannylation d'halogenures allyliques en serie cyclohexenique

cis- and trans-5-Methyl-2-cyclohexenyl chlorides were matallated by trimethylstannyllithium and tributylstannyllithium giving the corresponding allyltin compunds with inversion of configuration as shown by ¹³C and ¹¹⁹Sn NMR spectroscopy.     

Pulsed fourier transform NMR of substituted aryltrimethyltin derivatives : III. Proton data at 100 MHz and the derived Hammett σ-constant of the trimethyltin group

Proton NMR data at 100 MHz are reported for thirteen para- and meta-substituted phenyltrimethyltin compounds, XC₆H₄Sn(CH₃)₃, where X = para-N(CH₃)₂, para-OCH₃, para-OC₂H₅, para-CH₃, meta-CH₃, -H, para-F, meta-OCH₃, para-Cl, para-Br, meta-F, meta-Cl and para-Sn(CH₃)₃. Correlation coefficients with Hammett σ-constants of greater than 0.95 are obtained with the methyltin proton chemical shifts and coupling constants to carbon [¹J(¹³C¹H)] and tin [²J(SnC¹H)]. Solvent effects and other extraneous factors invalidate comparisons of ? values in terms of the relative attenuation of the transmission of substituent effects through homologous carbon, silicon, germanium and tin systems, but coupling constant data reflect a diminution of ca. one tenthfold per bond in the order ?[C(1)Sn] > ? [SnC] > ? [CH]. Satisfactory correlations (r > 0.95) are obtained in this series of closely-related compounds among the conventionally recorded two-bond, ²J(SnC¹H) and the constituent, one-bond ¹J (Sn¹³C) and J(¹³C¹H) coupling constants, but the correlation coefficient for the comparison between the two one-bond couplings, ¹J(Sn¹³C) and ¹J(¹³C¹H) is lower (r = 0.872). Changes in the couplings at the methyltin carbon bond tin-119 atoms are interpreted in terms of isovalent hybridization; a model based upon effective nuclear charges is tested with respect to both NMR coupling constants and ¹¹⁹Sn Mössbauer Isomer shifts at tin and is invalidated. Proton and carbon-13 NMR, chemical shift and coupling constant data are used to derive a Hammett σ-constant for the para-trimethyltin group of ?0.14, and the significance of this value is discussed.     

Long-range tin-tin coupling constants: II. Two-bond coupling via carbon

Tin-119 and carbon-13 NMR data for a total of 34 compounds containing the grouping Sn-C-Sn (C is either sp³- or sp²-hybridised) are presented and discussed. In organotin derivatives of alkanes, ²J(Sn-C-Sn) can only be correlated with ¹J(Sn-C₂) if a sign change for the former coupling is assumed. In most of the compounds of this type studied, ¹J(Sn-CH₃) is, due to rehybridisation and in contrast to the usual situation, larger than ¹J(Sn-C²); the same is true in some cases for distannylakenes, the behaviour of which is complicated by changes in the torsional angle about the carbon-carbon double bond. Thus correlation of ²J(Sn-C-Sn) with other spectral parameters is not possible in these cases. The total tin chemical shift range for compounds MeⁿSn(CH₂MME₃)_4-n (M  C, Si, Ge, Sn; n  0–4) is 140 ppm. Incorporation of a ditin fragment in a six-membered ring causes a downfield tin shift of 30 ppm.     

‘Anomalous’ 2J(Sn?H) coupling in mono– and dichloromethyltin compounds

The linear relationship between the coupling constants ¹J(Sn? ¹³C) and ²J(Sn? H), observed for a number of organotin compounds, does not hold for coupling in the Sn? CH_nCl_3?n group of mono- and dichloromethyltin compounds. A complete determination of all NMR parameters of the compounds Me₃Sn-CH_nCl_3?n (n = 0 to 3) shows no further anomalies, indicating that steric factors must be responsible for the unusually low values of ²J(Sn? H) in the SnCH_nCl_3?n group. Molecular weight measurements support this theory, showing that the chlorine-containing compounds are associated.     

Untersuchungen zum elektronischen einfluss von organylliganden: IV. 13C-NMR-spektroskopische untersuchung der gegenseitigen beeinflussung von organylliganden in triethylzinnorganylverbindungen

By means of ¹³C NMR spectroscopy, the coupling constants ¹J(¹¹⁹Sn¹³C_Et) of 18 compounds of the SnEt₃R type (R = organo group) have been measured. These coupling constants have been shown to reflect the change induced by R in the s-content of the tin hybrid orbitals of the SnCEt bonds. The series of the influence of R obtained on the basis of the coupling constant mentioned as a parameter is compared with a trans-influence series of R obtained on organo-mercury compounds. Occurring differences are attributed to different modes of bonding of the group R at the central atom.     

Dérivés Alléniques de l'Étain,du Plomb et du Mercure. Signes Relatifs des Constantes de Couplage Métal-Proton á Travers Deux et Quatre Liaisons

Satellites corresponding to metal-proton coupling constants through two and four bonds are observed in PMR spectra of Pb, Sn and Hg allenic derivatives. The relative signs of these coupling constants are deduced from analysis of the satellite spectra: ²J(X? H) and ⁴J(X? H) are of opposite signs for X = ²⁰⁷Pb, ¹¹⁹Sn, ¹¹⁷Sn and of same sign for X = ¹⁹⁹Hg. Probable absolute signs of reduced coupling constants are discussed in relation to published data: ²K(X? C? H) is probably positive for X = ²⁰⁷Pb, ¹¹⁹Sn, ¹¹⁷Sn and ¹⁹⁹Hg. ⁴K(X? C?C?C? H) is probably negative for X = ²⁰⁷Pb, ¹¹⁹Sn, ¹¹⁷Sn and positive for X = ¹⁹⁹Hg.     

A 31P and 119Sn NMR study of trichlorostannate derivatives of some chloride-bridged palladium(II) dimers

The chloride-bridged dimers [Pd(μ-Cl)(SnCl₃)L]₂ (L = P(p-tolyl)₃, P(p-C₆H₄OMe)₃, As(p-tolyl)₃, AsEt₃, PEt₃, PPrⁿ₃) have been synthesized and their ¹¹⁹Sn and, where relevant, ³¹P NMR spectra recorded. For the aryl phosphine and both arsine complexes the dimers exist as both the sym-trans and sym-cis isomers; however, for the PEt₃ and PPrⁿ₃ compounds, there is only one form, which we assign to the sym-trans structure. There is a geometric dependence of both ⁴J(¹¹⁹Sn, ¹¹⁷Sn) and ⁴J(¹¹⁹Sn, ³¹P). The dimeric complex with P(p-tolyl)₃ carbonylates 1-heptyne in the presence of excess SnCl₂, but is inactive in its absence.     

195Pt, 119Sn and 31P NMR studies of alkyl,aryl and acyl trichlorostannate complexes of platinum(II). The crystal structure of trans-[Pt(SnCl3)(COC6H5)(PEt3)2]

¹⁹⁵Pt, ¹¹⁹Sn and ³¹P NMR characteristics of the complexes trans-[Pt(SnCl₃)(carbon ligand)(PEt₃)₂] (1a-1e) are reported, (carbon ligand = CH₃ (1a), CH₂Ph (1b), COPh (1c), C₆Cl₅ (1d), C₆Cl₄Y (e); Y = meta- and para-NO₂, CF₃, Br, H, CH₃, OCH₃, or Pt(SnCl₃)(PEt₃)₂. The values of ¹J(¹⁹⁵Pt, ¹¹⁹Sn) vary from 2376 to 11895 Hz with the COPh ligand having the smallest and the C₆Cl₅ ligand the largest value, making a total range for this coupling constant, when the dimer syn-trans-[PtCl(SnCl₃)(PEt₃)]₂ is included, of ca. 33000 Hz. In the meta- and para-substituted phenyl complexes ¹J(¹⁹⁵Pt, ¹¹⁹Sn) (a) is greater for electron-withdrawing substituents, (b) varies more for the meta-substituted derivatives (5634 to 7906 Hz) than for the para analogues (6088 to 7644 Hz) and (c) has the lowest values when the Pt(SnCl₃)(PEt₃)₂ group is the meta- or para-substituent. The direction of the change in ¹J(¹⁹⁵Pt, ¹¹⁹Sn) is opposite to that found for ¹J(¹⁹⁵Pt, ¹¹⁹P). For the aryl complexes linear correlations are observed between δ(¹¹⁹Sn), ¹J(¹⁹⁵Pt, ¹¹⁹Sn), ¹J(¹⁹⁵Pt, ³¹P), ¹J(¹¹⁹Sn, ³¹P) and the Hammett substituent constant σⁿ. δ(¹¹⁹Sn) and ¹J(¹⁹⁵Pt, ¹¹⁹Sn) are related linearly to v(Pt-H) in the complexes trans-[PtH(C₆H₄Y)(PEt₃)₂]; δ(¹¹⁹Sn) and δ(¹H) (hydride) are also linearly related. Based on ¹J(¹⁹⁵Pt, ¹¹⁹Sn), the acyl ligand is suggested to have a very large NMR trans influence. The differences in the NMR parameters for (1a-e) are rationalized in terms of differing σ- and π-bonding abilities of the carbon ligands.The structure of 1c has been determined by crystallographic methods. The complex has a slightly distorted square planar geometry with trans-PEt₃ ligands. Relevant bond lengths (Å) and bond angles (°) are: PtSn, 2.634(1), PtP, 2.324(4) and 2.329(4), PtC, 2.05(1); PPtP, 170.7(6), SnPtC, 173.0(3), SnPtP, 92.1(1), 91.7(1), PPtC, 88.8(4) and 88.3(4). The PtSn bond separation is the longest yet observed for square-planar platinum trichlorostannate complexes, and would be consistent with a large crystallographic trans influence of the benzoyl ligand. The PtSn bond separation is shown to correlate with ¹J(¹⁹⁵Pt, ¹¹⁹Sn).     

Three‐centre Rh?H?Sn bonds: an NMR study of the effects of varying the electron density on rhodium

The complexes [Rh(X)(H)(SnPh₃)(PPh₃)(L)] (X = NCBPh₃ (a), N(CN)₂ (b), NCS (c), NCO (d), N₃ (e); L = 1‐methylimidazole) ( 1 ) show systematic changes in δ(¹¹⁹Sn), δ(¹⁰³Rh), J(¹¹⁹Sn–¹H) and J(¹¹⁹Sn–¹⁰³Rh) that are related to the electron‐donating properties of X. As X becomes more electron‐rich, δ(¹⁰³Rh), J(¹¹⁹Sn–¹H) and J(¹¹⁹Sn–¹⁰³Rh) increase and δ¹¹⁹Sn) decreases. The related complexes trans‐[Rh(X)(H)(SnPh₃)(PPh₃)₂(L)] (X = N(CN)₂, NCO; L = 4‐carboxymethylpyridine (x), pyridine (y) and 4‐dimethylaminopyridine (z)) ( 2 ), show a continuation of the trends in δ(¹¹⁹Sn) and J(¹¹⁹Sn–¹H), but not δ(¹⁰³Rh) or J(¹¹⁹Sn–¹⁰³Rh). Data for 1 and 2 show that within certain limits of type of ligand varied (X = N‐donor, L = a pyridine) and coordination geometry, the response of δ(¹¹⁹Sn) and J(¹¹⁹Sn–¹H) to changes in electron density on rhodium is largely independent of the means by which the change is effected.Copyright © 2001 John Wiley & Sons, Ltd.     

Substituent chemical shifts of the organotin moiety in compounds of the type RSnMenCl3 − n (n = 0 to 3; R = n-alkyl)

The ¹³C and ¹¹⁹Sn NMR spectra of 33 organotin compounds of the type RSnMe_nCl_{3 ? n} and related types are discussed. The substituent effects of the groups SnMe₃, SnMe₂Cl, SnMeCl₂ and SnCl₃ (and of some related groups) on the carbon chemical shifts in the alkyl group R have been determined; the SnMe₃ group causes a small upfield shift of the carbon attached to it, while the other groups cause downfield shifts. The shifts show a monotonic change on replacing methyl groups in Me₃Sn by chlorine atoms. The effects on carbons further removed from the tin atom are discussed. Variation in R causes little change in ⁿJ(Sn? C) or δ(¹¹⁹Sn).     

Über polystannane: II. I(t-Bu2Sn)4I,ein 1,4-difunktionelles tetrastannan

The compound I(t-Bu₂Sn)₄I has been synthesized by controlled cleavage of the related cyclotetrastannane (t-Bu₂Sn)₄ with iodine in toluene. Both compounds have been investigated by mass, NMR and vibrational spectra. I(t-Bu₂Sn)₄I: δ(¹¹⁹Sn_terminal) 67.7, δ(Sn_central) 17.4 ppm; ¹J(SnSn) 2199 (terminal-central) and 1575 (central-central), ²J(SnSn) 20 (terminal-central), ³J (SnSn) 307 Hz (terminal-terminal); ν(SnSn) 119, ν(SnI) 167 cm^?1. (t-Bu₂Sn)₄: δ(Sn) 87.4 ppm; ν(SnSn) 125 cm^?1. The crystal structure of I(t-Bu₂Sn)₄I has been determined (R = 0.071): bond lengths SnSn 289.5(1) (terminal-central) and 292.4(1) (central-central), SnI 275.3(1) pm. The conformation of the chain ISn₄I is all trans.     

13 C 183W-Kopplungen als sonde für metall—carbin-, —carbenund—alkyl-bindungen

Carbon-13 NMR data are reported for trimethyltin derivatives containing ER_n groups where E  C, Si, Ge, Sn, N, O and S including a series of cyclic amines with ring sizes from three to seven. Coupling constant values for the homologous series of fourth group derivatives give goood correlations with the electronegativity of E. The observation of the two-bond, ¦ ²J(¹¹⁹SnE¹³C) ¦ couplings only in the derivatives containing bulky R groups is rationalized by a bimolecular exchange of ER_n groups in the concentrated solutions studied.     

13C and 119Sn NMR spectra of Di-n-butyltin(IV) compounds

The ¹³C and ¹¹⁹Sn NMR spectra of a set of di-n-butyltin(IV) compounds and their complexes in coordinating and non-coordinating solvents have been studied. The results have shown that it is possible to describe semiquantitatively the shape of coordination polyhedra of these compounds from analysis of their δ(¹¹⁹Sn) and ¹J(¹¹⁹Sn-¹³C) parameters. The values of δ(¹¹⁹Sn) define the regions with different coordination numbers of the central tin atom, so that four-coordinate compounds have δ(¹¹⁹Sn) ranging from about + 200 to −60 ppm, five-coordinate compounds, −90 to −190 ppm, and six-coordinate compounds, −210 to −400 ppm. The values of ¹J(¹¹⁹Sn-¹³C) were used for the calculation of the CSnC angle in the coordination polyhedron of individual compounds.     

Preparation and spectroscopic studies of diorganotin oxycarbonates

The synthesis, ^119mSn Mössbauer and infrared spectra of a series of diorganotin oxycarbonates of the type, (R₂Sn)₂OCO₃·nH₂O, where R = Me, Et, Ph, n = 0; R = Pr, Bu, Oct, n = 1, are reported.Structures are proposed for these compounds in the solid state, on the basis of their spectroscopic data.     

The synthesis,NMR (1H, 13C, 119Sn) and IR spectral studies of some di‐ and tri‐organotin(IV) sulfonates: X‐ray crystal structure of [(n‐C4H9)2Sn(OSO2C6H4CH3‐4)2·2H2O]

A number of alkyltin(IV) paratoluenesulfonates, R_nSn(OSO₂C₆H₄CH₃‐4)_4?n (n = 2, 3; R = C₂H₅, n‐C₃H₇, n‐C₄H₉), have been prepared and IR spectra and solution NMR (¹H, ¹³C, ¹¹⁹Sn) are reported for these compounds, including (n‐C₄H₉)₂Sn(OSO₂X)₂ (X = CH₃ and CF₃), the NMR spectra of which have not been reported previously. From the chemical shift δ(¹¹⁹Sn) and the coupling constants ¹J(¹³C, ¹¹⁹Sn) and ²J(¹H, ¹¹⁹Sn), the coordination of the tin atom and the geometry of its coordination sphere in solutions of these compounds is suggested. IR spectra of the compounds are very similar to that observed for the paratoluenesulfonate anion in its sodium salt. The studies indicate that diorganotin(IV) paratoluenesulfonates, and the previously reported compounds (n‐C₄H₉)₂Sn(OSO₂X)₂ (X = CH₃ and CF₃), contain bridging SO₃X groups that yield polymeric structures with hexacoordination around tin and contain non‐linear C? Sn? C bonds. In triorganotin(IV) sulfonates, pentacoordination for tin with a planar SnC₃ skeleton and bidentate bridging paratoluenesulfonate anionic groups are suggested by IR and NMR spectral studies. The X‐ray structure shows [(n‐C₄H₉)₂Sn(OSO₂C₆H₄CH₃‐4)₂·2H₂O] to be monomeric containing six‐coordinate tin and crystallizes from methanol–chloroform in monoclinic space group C2/c. The Sn? O (paratoluenesulfonate) bond distance (2.26(2) Å) is indicative of a relatively high degree of ionic character in the metal–anion bonds. Copyright © 2003 John Wiley & Sons, Ltd.     

Studies on C-heterocyclic tin compounds. The synthesis and spectral characterization of some thienyl tetraorganotin(IV) compounds

The synthesis of a series of tetraorganotin(IV) compounds containing selectively the 2-thienyl, 3-thienyl, 5-methyl-2-thienyl, 5-t-butyl-2-thienyl, 4-methyl-2-thienyl and 3-(2-pyridyl)-2-thienyl groups [L], of formula R_4-nSn[L]_n (R = Ph, p-tolyl, Me, cyclopentyl, cyclohexyl; n = 1–4) is reported. Features of structural interest deduced from ^119mSn Mössbauer and NMR (¹³C and ¹¹⁹Sn modes) spectra are considered.     

Long-range nuclear spin-spin coupling between 11B and 13C, 29Si or 119Sn: a promising tool for structural assignment

The influence of unresolved long-range nuclear spin-spin coupling [ⁿJ(¹¹BX) (n > 1; X = ¹³C, ²⁹Si or ¹¹⁹Sn)] on X resonances has been studied for aminoboranes (1 and 2), haloboration (2 and 4), hydroboration (5) and organoboration products of alkynes (6 and 7). The differential broadening of X resonances in the X NMR spectra arising from ⁿJ(¹¹BX) (most obvious for X= ¹¹⁹Sn) shows a qualitatively useful pattern of various coupling pathways. |²J(¹³CN-¹¹B)| in 1 and 2 appears to be sensitive to the nature of the trans-ligand and to the ring rize. In many alkenylboranes (3, 4, 5b and d, 6 and 7) the magnitude of the coupling constants across the CC double bond follows the trend |²J(¹¹BX)| ∼ |³J(¹¹BX)|_cis < |³J(¹¹BX)|_trans. An increasing number of electropositive substituents at the CC double bond causes an increase in the magnitude of |³J(¹¹BX)|_cis,trans. If there are only organyl groups of hydrogen attached to the CC double bond, as in the hydroboration products of alkynes (5a and c) |ⁿJ(¹³C-¹¹B)| appears to be too small with respect to [T_Q(¹¹B)]⁻¹, and the differential broadening was neglibible under the experimental conditions used.