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Tong Ren

Publications and source records attributed to Tong Ren.

29 records · Page 2Linked to original sources
PubMed2003

Cyanide adducts on the diruthenium core of [Ru2(L)4](+) (L = ap, CH3ap, Fap, or F3ap). Electronic properties and binding modes of the bridging ligand.

The products of the reaction between CN(-) and four different diruthenium complexes of the type Ru(2)(L)(4)Cl where L = 2-CH(3)ap (2-(2-methylanilino)pyridinate anion), ap (2-anilinopyridinate anion), 2-Fap (2-(2-fluoroanilino)pyridinate anion), or 2,4,6-F(3)ap (2-(2,4,6-trifluoroanilino)pyridinate anion) are reported. Mono- and/or dicyano adducts of the type Ru(2)(L)(4)(CN) and Ru(2)(L)(4)(CN)(2) are found exclusively as reaction products when either the 2-CH(3)ap or the ap derivative is reacted with CN(-), but diruthenium complexes with formulations of the type Ru(2)(F(x)ap)(3)[mu-(o-NC)F(x-1)ap](mu-CN) or Ru(2)(F(x)ap)(4)(mu-CN)(2) (x = 1 or 3) are also generated when Ru(2)(Fap)(4)Cl or Ru(2)(F(3)ap)(4)Cl is reacted with CN(-). More specifically, four products formulated as Ru(2)(Fap)(4)(CN), Ru(2)(Fap)(4)(CN)(2), Ru(2)(Fap)(3)[mu-(o-NC)ap](mu-CN), and Ru(2)(Fap)(4)(mu-CN)(2) can be isolated from a reaction of CN(-) with the Fap derivative, but the exact type and yield of these compounds depend on the temperature at which the experiment is carried out. In the case of the F(3)ap derivative, the only diruthenium complex isolated from the reaction mixture has the formulation Ru(2)(F(3)ap)(3)[mu-(o-NC)F(2)ap](mu-CN) and this compound has structural, electrochemical, and spectroscopic properties quite similar to that of previously characterized Ru(2)(F(5)ap)[mu-(o-NC)F(4)ap](mu-CN). Both the mono- and dicyano derivatives synthesized in this study possess the isomer type of their parent chloro complexes. The Ru-Ru bond lengths of Ru(2)(ap)(4)(CN) and Ru(2)(2-CH(3)ap)(4)(CN) are longer than those of Ru(2)(ap)(4)Cl and Ru(2)(CH(3)ap)(4)Cl, respectively, and this is accounted for by the strong sigma-donor properties of the CN(-) ligand as compared to Cl(-). The Ru-C bonds in Ru(2)(ap)(4)(CN)(2) are significantly shorter than those in Ru(2)(ap)(4)(CN), thus revealing a greatly enhanced Ru-CN interaction in the dicyano adduct, a result which is also indicated by the fact that nu(CN) in Ru(2)(ap)(4)(CN)(2) is 50 cm(-1) higher than nu(CN) in Ru(2)(ap)(4)(CN). Although both (4,0) Ru(2)(ap)(4)(CN)(2) and (3,1) Ru(2)(Fap)(4)(CN)(2) possess the same formulation, there are clear structural differences between the two complexes and this can be explained by the fact that the two cyano derivatives possess a different binding symmetry of the bridging ligands. Each mono- and dicyano adduct was electrochemically investigated in CH(2)Cl(2) containing TBAP as supporting electrolyte. Ru(2)(ap)(4)(CN), Ru(2)(CH(3)ap)(4)(CN), and Ru(2)(Fap)(4)(CN) undergo one reduction and two oxidations. The two dicyano adducts of the ap and Fap derivatives are characterized by two reductions and one oxidation. The potentials of these processes are all negatively shifted in potential by 400-720 mV with respect to half-wave potentials for the same redox couples of the monocyano derivatives, with the exact value depending upon the specific redox reaction.

Journal Article↗
PubMed2003

Polyyn-diyls capped by diruthenium termini: a new family of carbon-rich organometallic compounds and distance-dependent electronic coupling therein.

Polyyn-diyls capped by Ru(2)(ap)(4) termini (ap = 2-anilinopyridinate), that is, [Ru2(ap)4](mu-C,C'-C2m)[Ru2(ap)4] (compounds 1-5 with m = 1-4 and 6), were synthesized through either a metathesis reaction between Ru2(ap)4Cl and LiC(2m)Li or a Glaser homocoupling reaction of Ru2(ap)4(CmH) under Eglinton/Hay conditions. X-ray diffraction studies of compounds 2 and 4 revealed both the linear rigid rod topology of these compounds and the fine structural details about the Ru2 cores and polyyn-diyl chains. Cyclic and differential pulse voltammetric (CV and DPV) measurements and spectroelectrochemical studies show that reduced and oxidized forms of 1, 2, 4, and 5 are donor-acceptor systems in which the Ru2 termini are coupled to varying degrees depending upon the length of the polyyn-diyl bridge.

Journal Article↗
PubMed2003

[Evaluation of surgical resection of pulmonary metastasis of trophoblastic tumour].

OBJECTIVE: To evaluate the role of lung lobectomy in the patients of tumor with lung metastases. METHODS: A total of 45 cases of trophoblastic tumor with pulmonary metastases treated by lung lobectomy from 1985-2002 at PUMC hospital was retrospectively analyzed. Seven cases were diagnosed as invasive mole and thirty-eight as choriocarcinoma. RESULTS: Lung lobectomy was performed in all of these patients after several courses of chemotherapy. Seven cases of invasive mole reached complete remission. Eleven cases of choriocarcinoma with stage IIIa had received average 13 courses of chemotherapy, 10 of them reached complete remission. Seventeen cases of choriocarcinoma with stage IIIb had received average 14.3 courses of chemotherapy, 11 of them reached complete remission. Ten cases of choriocarcinoma with stage IV had received average 15 courses of chemotherapy, six of them reached complete remission. In the 45 patients, histologic examination disclosed haemorrhagic necrotic tissue in 27 patients, 17 of them reached complete remission (63%). Histologic examination also revealed fibrosis around the focus in 16 patients, 14 of them reached complete remission (88%). Tuberculosis was found in 2 patients. CONCLUSIONS: Although the development of effective chemotherapy has resulted in improved survival of patients with gestational trophoblastic tumor, lung lobectomy remains an important adjunct treatment in a selected subset of patients. Pathological examinations can help to estimate the prognosis.

Adolescent↗
PubMed2002

Chemosensors for the marine toxin saxitoxin.

Eleven anthracylmethyl crown ethers have been synthesized and evaluated as fluorescence sensors for the marine toxin saxitoxin. Fluorescence enhancement data are consistent with a 1:1 binding complex for all crowns. The binding constants are in the range of 10(4) M(-)(1) in ammonium phosphate buffer (pH 7.1) in 80% ethanol solvent. Selectivity for sensing saxitoxin versus several organic analytes has been demonstrated for the first time. Possible modes of binding are presented, and relevance to saxitoxin monitoring programs are discussed.

Animals↗
PubMed2002

Tetrakis(N,N'-dimethylbenzamidinato)diruthenium(III) compounds bearing axial chloro and alkynyl ligands: a new family of redox rich diruthenium compounds.

Novel diruthenium(III) compound Ru(2)(DMBA)(4)Cl(2) (1, DMBA = N,N'-dimethylbenzamidinate) was obtained via refluxing Ru(2)(OAc)(4)Cl with dimethylbenzamidine in the presence of LiCl and Et(3)N under ambient atmosphere. Metathesis reactions between 1 and MC(2)Y (M = Li and Na) yielded bis-alkynyl derivatives Ru(2)(DMBA)(4)(C(2)Y)(2) (Y = SiMe(3) (2a), H (2b), Ph (2c), and C(2)SiMe(3) (3a)), and further desilylation of 3a using K(2)CO(3) resulted in Ru(2)(DMBA)(4)(C(4)H)(2) (3b). Compound 1 is paramagnetic (S = 1), while compounds 2 and 3 are diamagnetic. The single-crystal X-ray diffraction study revealed that the Ru-Ru distances are 2.3224(7), 2.4501(6), and 2.4559(6) A for 1, 2a, and 3b, respectively. A strong Ru-C sigma-bond in alkynyl adducts was implied by the short Ru-C distances in 2a (1.955(4) A) and 3b (1.952[5] A). All the compounds undergo three one-electron redox processes, an oxidation and two reductions, and the reversibility of redox couples depends on the nature of axial ligands.

Journal Article↗
PubMed2002

[Transfection of MDR1-mRNA into human mononuclear cells to improve their resistance to anticancer agents, an in vitro study].

OBJECTIVE: To investigate the expression and function of P-glycoprotein (P-gp), an efflux pump encoded by multidrug resistance complementary DNA (MDR1), in human mononuclear cells (MNCs) transfected with MDR1 mRNA. METHOD: Two kinds of human MDR1 mRNA, pT7TS-MDR1 and pGEM5Zf (+)-MDR1 with difference in the 5' and 3' untranslated regions only, were constructed and modified and then were transfected into human MNCs rich in hematopoietic progenitor cells from a patient with small cell lung cancer. The expression efficiency and pump function of P-gp were measured with FACS. Rhodomine 123 efflux test was used to examine the function of P-gp. Un- transfected mononuclear cells from the same person were used as controls. RESULT: The expression of P-gp 12 hours after transfection was 2.16 % in control group, 8.94% in pGEM5Zf (+)-MDR1 group, and 19.14% in pT7TS-MDR1 group. The expression of P-gp 72 hours after transfection was 2.12% in control group, 6.12% in pGEM5Zf(+)-MDR1 group, and 10.71% in pT7TS-MDR1 group, significantly higher in the third group. Rhodamine-123 efflux test showed that the efflux-pump function of P-gp 12 hours after the trransfection was 19.20% in control group, 25.59% in GEM5Zf (+)- MDR1 group, and 35.02% in pT7TS-MDR1 group (all P < 0.01). The expression and presence of P-gp by transfected cells lasted at least 72 hours. CONCLUSION: Transfection of human mononuclear cells with MDR1 mRNA significantly increases their resistance to anticancer agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Linear Free Energy Relationships in Dinuclear Compounds. 2. Inductive Redox Tuning via Remote Substituents in Quadruply Bonded Dimolybdenum Compounds.

Syntheses and characterizations are reported for dimolybdenum(II) compounds supported by the diarylformamidinate (ArNC(H)NAr(-)) ligand, where Ar is XC(6)H(4)(-), with X as p-OMe (1), H (2), m-OMe (3), p-Cl (4), m-Cl (5), m-CF(3) (6), p-COMe (7), p-CF(3) (8), or Ar is 3,4-Cl(2)C(6)H(3)(-) (9) or 3,5-Cl(2)C(6)H(3)(-) (10). The (quasi)reversible oxidation potentials measured for the Mo(2)(5+)/Mo(2)(4+) couple were found to correlate with the Hammett constant (sigma(X)) of the aryl substituents according to the following equation: DeltaE(1/2) = E(1/2)(X) - E(1/2)(H) = 87(8sigma(X)) mV. Molecular structure determinations of compounds 1, 2, 5, and 10 revealed an invariant core geometry around the Mo(2) center, with statistically identical Mo-Mo quadruple bond lengths of 2.0964(5), 2.0949[8], 2.0958(6), and 2.0965(5) Å, respectively. Magnetic anisotropies for compounds 1-10 estimated on the basis of (1)H NMR data were similar and unrelated to sigma(X). Similarity in UV-vis spectra was also found within the series, which, in conjunction with the features of both molecular structures and (1)H NMR spectra, was interpreted as the existence of a constant upper valence structure across the series. Results of Fenske-Hall calculations performed for several model compounds paralleled the experimental observations.

Journal Article↗