A multinuclear (1H, 31P, 199Hg) nuclear magnetic resonance study of some complexes of mercury(II) with ditertiary phosphines

1985 ◽  
Vol 63 (11) ◽  
pp. 2829-2839 ◽  
Author(s):  
Philip A. W. Dean ◽  
Radhey S. Srivastava
Keyword(s):  
Spectral Properties ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Mixed Ligand Complex ◽  
Nuclear Magnetic Resonance Study ◽  
Chelate Complexes ◽  
Ligand Complex ◽  
The One ◽  
Reduced Temperature ◽  
Chelate Ring Size

From Hg(SbF6)2 and an appropriate amount of the ligands Ph2PCHRPPh2 (R = H or Me), 2:2, 1:2, and 1:3 M:L complexes have been prepared in MeNO2 solution and characterized by 1H, 31P, and 199Hg nmr spectroscopy. The 2:2 complexes are ligand-bridged, as are [Hg(Ph2PCH2PPh2)(Ph2PCHMePPh2)Hg]4+ and [Hg(Ph2PCH2PPh2)2Ag]3+ (prepared from Hg(SbF6)2, Ag(AsF6), or Ag(SbF6) and the ligand), examined by nmr for comparison. The complex [Hg(μ-Ph2PCHMePPh2)2Hg]4+ exists as two isomers, which interconvert slowly on the preparative timescale. The 1:2 complexes, and the analogous mixed ligand complex are shown by their nmr spectral properties to be examples of tetrahedral bis(chelate) complexes, which are very unusual for the Ph2PCHRPPh2 ligands. In the 1:3 complexes, and the one of the two possible mixed complexes identified, both η1-and η2-ligands appear to be present and these undergo rapid intramolecular η1-to-η2 exchange. The η1-bonding mode of Ph2PCH2PPh2 also occurs in [(η-Ph2P(CH2)2PPh2)Hg(η1-Ph2PCH2PPh2)2]2+ and [Hg(η1-Ph2PCH2PPh2)4]2+ as evidenced by their reduced temperature 31P nmr spectra in Me2CO—MeNO2.The complex [Hg(η2-Ph2PCH2PPh2)2]2+ has 31P and 199Hg nmr spectral properties significantly different from those of its acyclic analog [Hg(PMePh2)4]2+. To place this anomaly in perspective, the 31P and 199Hg nmr spectra of a much wider series of new bis(chelate) complexes [Hg(LL)(L′L′)]2+ have been obtained, with the ligand combinations LL = L′L′ = Ph2PNPhPPh2; LL = dppm, L′L′ = Ph2PNPhPPh2; LL = L′L′ = Ph2P(CH2)nPPh2(n = 2–4); LL = Ph2P(CH2)mPPh2, L′L′ = Ph2P(CH2)nPPh2 (m ≠ n; m = 1–3, n = 1–5). From the data for the last two series, it is found that only the bis(chelate) complex of Ph2PCH2PPh2 shows a large anomaly in its 199Hg chemical shift (anomalously high shielding), and that in [Hg(LL)(L′L′)]2+ values of 2J(PP), 1J(HgP), and 31P chemical shifts vary systematically with the ligand combination; of particular note, 1J(HgP) to LL decreases as the chelate ring size of L′L′ increases. These observations are discussed in terms of the variation in the intra-and inter-chelate PHgP angles expected in the complexes.

Antimony-121 nuclear magnetic resonance study of hexahaloantimonate anions

1981 ◽  
Vol 59 (20) ◽  
pp. 2940-2949 ◽  
Author(s):  
R. Garth Kidd ◽  
H. Garth Spinney
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectra ◽  
Central Atom ◽  
Chemical Shifts ◽  
Nuclear Magnetic Resonance Study ◽  
Acetonitrile Solution ◽  
Trans Isomers ◽  
Magnetic Resonance Study ◽  
Chlorine Substitution ◽  
Nuclear Shielding

The seven hexahaloantimonate anions in the series [SbClnBr6−n]− have been prepared and their antimony-121 nmr spectra show that for [SbCl4Br2]−, [SbCl3Br3]−, and [SbCl2Br4]−, only the cis isomers are present in acetonitrile solution. The pairwise additivity model for central atom shielding has been used for configuration assignments. Models relevant to the higher incidence of cis over trans isomers are discussed. The nuclear shielding of 121Sb is the most sensitive to halogen substitution of all the elements whose halide chemical shifts have been studied. Antimony shieldings exhibit normal halogen dependence, with bromine substitution causing upfield shifts relative to chlorine substitution.

The phosphorus-31 and metal nuclear magnetic resonance spectra of complexes of tin(II) and lead(II) with tricyclohexylphosphine oxide, sulfide, and selenide

1982 ◽  
Vol 60 (23) ◽  
pp. 2921-2926 ◽  
Author(s):  
Philip A. W. Dean
Keyword(s):  
High Field ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Temperature Gradients ◽  
Large Temperature ◽  
Linear Variation ◽  
Small Temperature ◽  
Nuclear Magnetic Resonance Spectra ◽  
Small Temperature Variation ◽  
Reduced Temperature

The new stannous and plumbous complexes M(OP(C6H11)3)n2+ (n = 2 or 3, M = Sn or Pb) and [M(SP(C6H11)3)x(SeP-(C6H11)3)3−x]2+ (M = Sn or Pb) have been prepared in SO2 solution and characterized by their reduced temperature slow-exchange 31P and metal (119Sn or 207Pb) nmr spectra. No evidence could be found for complexes in which both OP(C6H11)3 and EP(C6H11)3 (E = S or Se) are coordinated to tin(II) or lead(II). The same pattern of chemical shifts is found in the 119Sn and 207Pb nmr spectra: δM(M(OP(C6H11)3)22+) < δM(M(OP(C6H11)3)32+ < δM(M(SP(C6H11)3)32+) < δM(M(SeP(C6H11)3)32+) and a monotonic but non-linear variation of δM with x for [M(SP(C6H11)3)x(SeP(C6H11)3)3−x]2+. From M(AsF6)2 in SO2 as reference, the range of the metal chemical shifts is 999–2079 ppm and 2407–7707 ppm in the 119Sn and 207Pb nmr spectra respectively. In the 31P nmr spectra, all of the appropriate two-bond M—P couplings are observed, but the fine structure expected from coupling to 31P could not always be observed in those metal nmr spectra which were measured at high field; it is suggested that these metal nmr spectra are "smeared out" by a combination of large temperature sensitivity of the metal chemical shifts and the small temperature variation allowed by the nmr spectrometer temperature controller and/or diffusion along any temperature gradients present along the length of the nmr sample.

scholarly journals Preparation, spectral characterization and antibacterial studies of silver(I) complexes of 2-mercaptopyridine and thiomalate

2008 ◽  
Vol 22 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Muhammad Hanif ◽  
Aisha Saddiqa ◽  
Shahida Hasnain ◽  
Saeed Ahmad ◽  
Ghulam Rabbani ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Mixed Ligand Complex ◽  
Inhibition Zone ◽  
Mixed Ligand ◽  
Ligand Complex ◽  
Antibacterial Studies ◽  
Activity Inhibition ◽  
High Antibacterial Activity ◽  
Ir And Nmr Spectroscopy ◽  
C Nmr

Silver(I) complexes of 2-mercaptopyridine (Mpy), [Ag(Mpy)]NO3and [Ag(Mpy)2]NO3, and the first mixed-ligand complex having a thione and thiolate coordinated to Ag(I), [Mpy–Ag–Tm] (Tm═thiomalate) have been prepared and characterized by IR and NMR spectroscopy. The1H and13C NMR spectra show the presence of both ligands in the mixed-ligand complex, [Mpy–Ag–Tm]. An upfield shift is observed in the >C═S resonance of Mpy and C═O resonances of thiomalate in13C NMR, while the other resonances are shifted downfield. The complexes showed relatively high antibacterial activity (inhibition zone of 6–11 mm) against a gram +ve bacterium,Bacillus subtilis, as compared to that (inhibition zone of 4 mm) against a gram –ve bacterium,Escherichia coli.

A tellurium-125 and tin-119 Mössbauer and nuclear magnetic resonance study of the group IV organotellurides

1986 ◽  
Vol 64 (5) ◽  
pp. 980-986 ◽  
Author(s):  
C. H. W. Jones ◽  
R. D. Sharma ◽  
S. P. Taneja
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Nuclear Magnetic Resonance Study ◽  
Group Iv ◽  
Magnetic Resonance Study ◽  
Nmr Chemical Shifts ◽  
Nmr Parameters ◽  
Nmr Data ◽  
Mössbauer Data ◽  
Cyclic Compounds

The 125Te Mössbauer and nmr spectra of the compounds (R3X)2Te(R = Me, X = C, Si, Ge, and Sn; R = Ph, X = Ge and Sn), R3MTePh (R = Me, X = Si, Ge, and Sn; R = Ph, X = Ge, Sn, Pb), R2Sn(TePh)2 (R = Me and t-Bu), and the cyclic compounds (Me2SnTe)3, (Me2Sn)3Te2, and (t-Bu2SnTe)2 have been measured. The trends in the Mössbauer and nmr data are discussed. The Mössbauer quadrupole splittings increase as the nmr chemical shifts become more positive, corresponding to a decrease in the shielding at the tellurium nucleus. The 119Sn Mössbauer and nmr parameters of the compounds (R3Sn)2E andR3SnEPh (R = Me and Ph), (Me2SnE)3, (Me2Sn)2E2, (t-Bu2SnE)2, and Me2Sn(EPh)2 (E = S, Se, and Te) are discussed. The 119Sn Mössbauer quadrupole splittings are again observed to increase as the nmr chemical shifts become more positive. The 125Te and 119Sn nmr and Mössbauer data provide evidence that there is little transmission of bonding effects through the tin–tellurium bond as the chemical environment about the tin or tellurium is changed.

NMR spectral properties of 16 synthetic bacteriochlorins with site-specific 13C or 15N substitution

2014 ◽  
Vol 18 (06) ◽  
pp. 433-456 ◽  
Author(s):  
Chih-Yuan Chen ◽  
Masahiko Taniguchi ◽  
Jonathan S. Lindsey
Keyword(s):  
Spectral Properties ◽  
Nmr Spectra ◽  
Inner Core ◽  
Chemical Shifts ◽  
Spectroscopic Properties ◽  
Coupling Constants ◽  
Substitution Effects ◽  
Free Base ◽  
Site Specific ◽  
Direct Inspection

The 1 H , 13 C , and 15 N nuclear magnetic resonance (NMR) spectral properties have been examined of a family of synthetic bacteriochlorins wherein each member incorporates a pair of 13 C or 15 N atoms. The atom locations span the inner core of the macrocycle: (1) 15 N at the 21,23- or 22,24-positions; (2) 13 C at the meso- (5,15- or 10,20-) positions; (3) 13 C at the pyrrole α-positions (1,11- or 4,14-positions); and (4) 13 C at the pyrroline α-positions (6,16- or 9,19-positions). Each bacteriochlorin lacks peripheral substituents other than a geminal dimethyl group at the 8- and 18-positions to preclude adventitious dehydrogenation. In total, eight free base and eight zinc bacteriochlorin isotopologs were examined to directly assign 1 H , 13 C and 15 N resonances of the macrocycle skeleton. Complete and unambiguous assignments, including those for all tertiary and quaternary carbons, were accomplished chiefly by direct inspection of 1D NMR spectra of each isotopolog. Coupling constants (1 H –1 H , 13 C –1 H , 15 N –1 H , 13 C –13 C and 15 N –13 C ), which are rarely reported for tetrapyrroles, also were extracted. The 1 H and 13 C chemical shifts were then compared to those of unsaturated analogs (chlorin, porphyrin) and natural bacteriochlorophylls. The comprehensive set of NMR spectroscopic properties of sparsely substituted bacteriochlorins provides valuable information for understanding substitution effects and aromaticity in structurally more elaborate counterparts.

A 113Cd nuclear magnetic resonance study of some complexes of cadmium with phosphine oxides, sulfides, and selenides

1981 ◽  
Vol 59 (23) ◽  
pp. 3221-3225 ◽  
Author(s):  
Philip A. W. Dean
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Phosphine Oxide ◽  
Nmr Spectra ◽  
Nuclear Magnetic Resonance Study ◽  
Phosphine Oxides ◽  
Cd Spectra ◽  
Magnetic Resonance Study ◽  
Slow Exchange ◽  
Reduced Temperature

113Cd(AsF6)2 has been synthesized from 113CdO by treatment in SO2 with PF5 then AsF5. From the 113Cd-enriched salt have been prepared [Cd(EPR3)4]2+ (E = O, R = C6H11; E = S or Se, R = Ph), [Cd(SP(C6H11)3)x(SeP(C6H11)n−x]2+ (n = 4, x = 0–4; n = 3, x = 0–3), [Cd(EP(o-C6H4Me)3)n]2+ (E = S, n = 4 or 2; E = Se, n = 3 or 2), [Cd(Ph2P(O)(CH2)nP(O)Ph2)3]2+ (n = 1 or 2), and [Cd(Ph2P(O)((CH2)2P(O)Ph2)2)2]2+ in liquid SO2. The reduced temperature slow exchange 31P and 113Cd nmr spectra have been measured and are discussed. The 31P nmr are as expected from previous work on complexes containing 113Cd at natural abundance except that several values of 2J(113Cd—O—31P) have been measured. From the 113Cd spectra the most important shielding sequences observed are [Formula: see text] for [Cd(EP(C6H11)3)4]2+, δ2:1 < δ3:1 < δ4:1 for [Cd(EPR3)n]2+ (E = S or Se, n = 1–4, constant R), and [Formula: see text] for the various phosphine oxide complexes studied.The synthesis of SO2-insoluble Cd(SbF6)2•3(OP(C6H11)3) is reported.

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