Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TLX”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Chemokine receptor expression by neural progenitor cells in neurogenic regions of mouse brain.

We previously demonstrated that chemokine receptors are expressed by neural progenitors grown as cultured neurospheres. To examine the significance of these findings for neural progenitor function in vivo, we investigated whether chemokine receptors were expressed by cells having the characteristics of neural progenitors in neurogenic regions of the postnatal brain. Using in situ hybridization we demonstrated the expression of CCR1, CCR2, CCR5, CXCR3, and CXCR4 chemokine receptors by cells in the dentate gyrus (DG), subventricular zone of the lateral ventricle, and olfactory bulb. The pattern of expression for all of these receptors was similar, including regions where neural progenitors normally reside. In addition, we attempted to colocalize chemokine receptors with markers for neural progenitors. In order to do this we used nestin-EGFP and TLX-LacZ transgenic mice, as well as labeling for Ki67, a marker for dividing cells. In all three areas of the brain we demonstrated colocalization of chemokine receptors with these three markers in populations of cells. Expression of chemokine receptors by neural progenitors was further confirmed using CXCR4-EGFP BAC transgenic mice. Expression of CXCR4 in the DG included cells that expressed nestin and GFAP as well as cells that appeared to be immature granule neurons expressing PSA-NCAM, calretinin, and Prox-1. CXCR4-expressing cells in the DG were found in close proximity to immature granule neurons that expressed the chemokine SDF-1/CXCL12. Cells expressing CXCR4 frequently coexpressed CCR2 receptors. These data support the hypothesis that chemokine receptors are important in regulating the migration of progenitor cells in postnatal brain.

Animals↗

Transforming potential of the T-cell acute lymphoblastic leukemia-associated homeobox genes HOXA13, TLX1, and TLX3.

The importance of HOXA genes in T-cell acute lymphoblastic leukemia (T-ALL) has recently been recognized. We report a novel chromosomal translocation in a T-ALL patient that maps upstream of the HOXA13 gene and downstream of the BCL11B/CTIP2 locus. Analysis of HOXA gene transcription demonstrated massive expression of HOXA13, whereas the other HOXA genes were unaffected. A genomic rearrangement of the HOXA locus associated with exclusive expression of HOXA13 was observed in a second patient. This situation resembles chromosomal translocations activating genes of the TLX/HOX11 family in T-ALLs. To compare the leukemogenic properties of HOXA13 to that of TLX proteins, cohorts of lethally irradiated mice were transplanted with bone marrow transduced with a retroviral vector expressing TLX3 or HOXA13. Cells transduced with TLX3 or HOXA13 could not be detected in the peripheral blood of mice post-transplantation and none of the mice developed malignancies. Cotransduction of the HOX cofactor MEIS1 with TLX3 or HOXA13 did not alter this outcome. However, in a myeloid clonogenic assay HOXA13 and TLX3 extended the proliferation of progenitors similarly to what was observed for TLX1. Altogether, our results strongly suggest the absolute requirement for cooperative events in association with homeobox gene up-regulation to induce T-cell leukemogenesis.

Adolescent↗

Ancient complexity of the non-Hox ANTP gene complement in the anthozoan Nematostella vectensis: implications for the evolution of the ANTP superclass.

The origin and evolution of ANTP superclass genes has raised controversial discussions. While recent evidence suggests that a true Hox cluster emerged after the cnidarian bilaterian split, the origin of the ANTP superclass as a whole remains unclear. Based on analyses of bilaterian genomes, it seems very likely that clustering has once been a characteristic of all ANTP homeobox genes and that their ancestors have emerged through several series of cis-duplications from the same genomic region. Since the diploblastic Cnidaria possess orthologs of some non-Hox ANTP genes, at least some steps of the expansion of this hypothetical homeobox gene array must have occurred in the last common ancestor of both lineages--but it is unknown to what extent. By screening the unassembled Nematostella genome, we have identified unambiguous orthologs to almost all non-Hox ANTP genes which are present in Bilateria--with the exception of En, Tlx and (possibly) Vax. Furthermore, Nematostella possesses ANTP genes that are missing in some bilaterian lineages, like the rough gene or NK7. In addition, several ANTP homeobox gene families have been independently duplicated in Nematostella. We conclude that the last cnidarian/bilaterian ancestor already harboured the almost full complement of non-Hox ANTP genes before the Hox system evolved.

Animals↗

The synergistic tumoricidal activity of anticancer drugs and oxidative burst-triggered macrophages.

The anticancer drugs adriamycin (ADR) and actinomycin D (AMD) were tested for their effect on the oxidative burst (OB) of mouse peritoneal macrophages (MPM) and on the killing of tumor cells by OB-stimulated MPM. The oxidative burst of MPM determined by hydrogen peroxide (H2O2) production was severely impaired by ADR (10 micrograms/ml) and AMD (40 micrograms/ml) after a 1 h treatment and by lower concentrations of the drugs following a 24 h treatment. The toxicity of the drugs against MPM was comparable to their effect on EL4 cells. Pretreatment of EL4 and TLX-9 tumor cells with sublethal amounts of ADR for 4 h rendered the cells sensitive to the cytotoxic effect of OB-stimulated MPM which were otherwise unable to kill these cells. It seems that anticancer drugs and OB-stimulated macrophages can cooperate in the destruction of tumor cells in vitro.

Animals↗

The effects of a mobile telephone task on driver behaviour in a car following situation.

The effects of a mobile telephone task on young and elderly drivers' choice reaction time, headway, lateral position, and workload were studied when the subjects were driving in a car-following situation, in the VTI driving simulator. It was found that a mobile telephone task had a negative effect upon the drivers' choice reaction time, and that the effect was more pronounced for the elderly drivers. Furthermore, the subjects did not compensate for their increased reaction time by increasing their headway during the phone task. The subjects' mental workload, as measured by the NASA-TLX, increased as a function of the mobile telephone task. No effect on the subjects' lateral position could be detected. Taken together, these results indicate that the accident risk can increase when a driver is using the mobile telephone in a car following situation. The reasons for the increased risk, and possible ways to eliminate it, are also discussed.

Accidents, Traffic↗

Very fast ultracentrifugation of serum lipoproteins: influence on lipoprotein separation and composition.

A very short run time and small sample volumes in the separation of lipoproteins by preparative ultracentrifugation are needed for several investigations. Recently, a very fast sequential separation method was described that needs only 100 min for one run in a centrifugal field of 625,000 x g. We studied the influence of centrifugal fields of this dimension on lipoprotein separation and lipoprotein particle integrity using a Beckman Optima TLX ultracentrifuge with a TLA-120.2 rotor. Rotor speed (120/90/60/30.10(3) rev./min) and run time (100 min/3 h/6.7 h/27 h) were selected in such a way that the product of centrifugal field and run time remained constant. The first conditions correspond to the very fast ultracentrifugation (VFU) procedure with a centrifugal field of 625,000 x g. Thirty different plasma samples covering a wide range of lipid and protein concentrations were separated in the course of two centrifugal runs at densities of 1.006 and 1.063 kg/l which yielded very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and the subnatant of low-density lipoproteins, including high-density lipoproteins (HDL) and concomitant sedimented plasma proteins. The major lipid components of the lipoproteins, triacylglycerols, free and esterified cholesterol, phospholipids and the apolipoproteins B and A-I, were estimated considering the masses of the tube contents after a slicing procedure. Measurements of lipids and proteins showed a very good recovery of better than 94% and 91%, respectively, and precision-within-series (coefficient of variation) of better than 4.2% and 6.5%, respectively. The effects of the rotor speed on the lipoprotein structure appeared to be weak. With increasing rotor speed, VLDL and LDL lipid constituents principally tended to decrease, whereas they increased in the subnatant of the LDL-run. The mean lipoprotein mass composition, considering the mass percentage of each measured particle constituent, did not show significant alterations. Total protein decreased in VLDL and in LDL and increased in the subnatant of the LDL-run. As checked by an enzyme-linked immunosorbent assay (ELISA) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), the protein effects were due to nearly complete disappearance of contaminating plasma proteins, especially albumin as the major contamination of VLDL and LDL. The apolipoproteins (apo) B-100, A-I, E and C-I to C-III remained nearly unaffected. The main advantages of VFU were the very short run time (cumulative flotation time is 3.4 h) and the elemination of albumin without repeated runs. The procedure was suitable for the assessment of lipid and protein constituents in lipoproteins from very small plasma samples (500 microliters).

Adult↗

Intrasplenic immunization for production of monoclonal antibodies against mouse blastocysts.

Applying the intrasplenic immunization method monoclonal antibodies were raised against trophectoderm of mouse blastocysts. Adhesive C57BL/6 blastocysts, obtained 18 h after estrogen reactivation from an experimental delay of implantation, and irradiated with 5000 rad were used as immunogen. Male DBA/2 mice were immunized by four intrasplenic depositions of about ten blastocysts each. The sensitized spleen cells were fused with mouse plasmacytoma cells on the 5th day after the last booster, followed by isolation of hybridoma clones by conventional monoclonal antibody procedures. 82 hybridoma clones were obtained of which two produced IgM antibodies recognizing trophoblast determinants. Absorbing the monoclonal antibodies with C57BL/6 splenic leukocytes followed by immunolabelling of blastocysts demonstrated that the antibodies recognized neither MHC nor TLX antigens. Pre- and peri-implantation stages were mapped by indirect immunofluorescence microscopy. Morulae were negative while blastocysts were positively labeled. Adhesive blastocysts labeled more strongly than delayed blastocysts. Cultured blastocysts showed an intense labeling of some of the trophoblast cells, while other trophoblast cells were unlabeled.

Animals↗

Sleepiness in professional drivers: effect of age and time of day.

The effect of age and time of day on objective and subjective sleepiness in professional drivers was investigated during a simulated driving task. Thirty-six young and middle-aged professional males drivers, free from any sleep disorder, took part in two simulated driving sessions; one carried out in the afternoon (between 2 and 4 p.m.) the other in the evening (between 11 p.m. and 1 a.m.). Half of each age group drove in a low traffic condition while the second half drove in a heavy traffic condition. Throughout the driving task, subjects' electroencephalogram and Karolinska sleepiness scale (KSS) scores were recorded. Visual analog scales measuring alertness and sleepiness levels were also completed before and after the driving. After each session, subjects filled out the NASA-TLX questionnaire and were asked if they had felt sleepy during the driving. Young professional drivers presented a significant decrease in alertness (raise of the spectral power in the alpha band) in the low traffic condition and a strong propensity to sleep during the evening test in contrast to middle-aged professional drivers.

Adult↗

Emergency physicians' behaviors and workload in the presence of an electronic whiteboard.

BACKGROUND: As the demands on the emergency medicine (EM) system continue to increase, improvements in the organization of work and the access to timely clinical and system information will be required for providers to manage their workload in a safe and efficient manner. Information technology (IT) solutions are beginning to find their place in the emergency department (ED) and it is time to begin understanding how these systems are effecting physician behavior, communication and workload. METHODS: The study used a time-in-motion, primary task analyses to study faculty and resident physician behavior in the presence of an electronic whiteboard. The NASA-Task Load Index (TLX) was used to measure subjective workload and the underlying dimensions of workload at the end of each physician observation. Work, communication and workload were characterized using descriptive statistics and compared using Mann-Whitney U-tests. RESULTS: Physicians in our study performed more tasks and were interrupted less than physicians studied previously in conventional EDs. Interruptions interrupted direct patient care tasks less than other clinical activities. Temporary interruptions appear to be a major source of inefficiency in the ED, and likely a major threat to patient safety. Face-to-face interruptions persist even in the presence of advanced IT systems, such as the electronic whiteboard. Faculty physicians exhibited lower workload scores than resident physicians. Frustration was a significant contributing factor to workload in resident physicians. All physicians ranked temporal demands and mental demands as major contributing factors to workload. CONCLUSION: The results indicate that the electronic whiteboard improves the efficiency of work and communication in the ED. IT solutions may have great utility in improving provider situational awareness and distributing workload among ED providers. The results also demonstrate that IT solutions alone will not solve all problems in the ED. IT solutions will probably be most effective in improving efficiency and safety outcomes when paired with human-based interventions, such as crew resource management. Future studies must investigate team interaction, workload and situational awareness, and the association of these factors to patient and provider outcomes.

Electronics↗

Nondominant Hand Training in Laparoscopy for Surgical Interns: Feasibility and Impact.

OBJECTIVE: Laparoscopy requires bimanual proficiency, yet early trainees demonstrate underdeveloped nondominant hand (NDH) performance. Although deliberate practice of NDH skill contributes to overall performance, NDH training is rarely incorporated into residency simulation curricula and has not been formally evaluated in surgical trainees. We assessed feasibility and impact of integrating structured NDH training with established laparoscopic curriculum for surgery interns. DESIGN: Prospective, single-institution randomized pilot study. Interns were assigned the standard 4-week curriculum of laparoscopic dominant hand and bimanual tasks (Control) or completed assigned NDH tasks in addition to the standard curriculum (Intervention). Feasibility was determined by assigned task completion, daily standard and NDH-specific self-reported practice time, and improvement in bimanual task performance. Performance was video recorded weekly and assessed by blinded evaluators using MISTELS and GOALS scoring. Cognitive workload during laparoscopic tasks was measured via NASA-TLX. Exploratory analyses were conducted within a Bayesian framework. SETTING: A single academic institution with a surgical simulation training program. PARTICIPANTS: General surgery interns on their 4-week simulation rotation. RESULTS: Eleven general surgery interns (6 intervention, 5 controls; all right-hand dominant) completed the study with 100% task completion and practice log compliance. Both groups improved in bimanual performance and perceived cognitive load. Reduction in cognitive workload during bimanual task performance was greater in the NDH group. Time spent on NDH practice over 4 weeks was associated with improved bimanual performance, independent of time spent on standard curriculum tasks. CONCLUSIONS: Structured NDH training is feasible to implement within an existing curriculum and reduces perceived cognitive workload during bimanual laparoscopic tasks. NDH practice demonstrates a beneficial dose-response relationship with performance, supporting its integration into early laparoscopic training.

Laparoscopy↗

The zebrafish orphan nuclear receptor genes nr2e1 and nr2e3 are expressed in developing eye and forebrain.

Mammalian Nr2e1 (Tailless, Mtll or Tlx) and Nr2e3 (photoreceptor-specific nuclear receptor, Pnr) are highly related orphan nuclear receptors, that are expressed in eye and forebrain-derived structures. In this study, we analyzed the developmental expression patterns of zebrafish nr2e1 and nr2e3. RT-PCR analysis showed that nr2e1 and nr2e3 are both expressed during embryonic and post-embryonic development. To examine the spatial distribution of nr2e1 and nr2e3 during development whole-mount in situ hybridization was performed. At tailbud stage, initial nr2e1 expression was localized to the rostral brain rudiment anterior to pax2.1 and eng2 expression at the prospective midbrain-hindbrain boundary. During subsequent stages, nr2e1 became widely expressed in fore- and midbrain primordia, eye and olfactory placodes. At 24hpf, strong nr2e1 expression was detected in telencephalon, hypothalamus, dorsal thalamus, pretectum, midbrain tectum, and retina. At 2dpf, the initially widespread nr2e1 expression became more restricted to distinct regions within the fore- and midbrain and to the retinal ciliary margin, the germinal zone which gives rise to retina and presumptive iris. Expression of nr2e3 was exclusively found in the developing retina and epiphysis. In both structures, nr2e3 expression was found in photoreceptor cells. The developmental expression profile of zebrafish nr2e1 and nr2e3 is consistent with evolutionary conserved functions in eye and rostral brain structures.

Amino Acid Sequence↗

Nuclear receptors in human immune cells: expression and correlations.

Nuclear receptors (NR) are key modulators of gene transcription. Their activity is ligand induced and modulates a large variety of tissue-specific cellular functions. However, for many NR little is known about their role in cells of the immune system. In this study, expression patterns and distribution of 24 NR were investigated in human peripheral blood mononuclear cells. We provide the first evidence of the expression of the 12 receptors CAR, CoupTFalpha, CoupTFbeta, FXR, GCNF, HNF4alpha, PPARbeta/delta, PXR, RevErbbeta, TR2, TR4 and TLX in highly purified CD4, CD8, CD19, CD14 cells. The expression profile of RevErbalpha and LXRalpha previously observed in B cell and macrophages, respectively, has been extended to CD4, CD8 and CD14 cells. Except for RARbeta, which was absence in any of the cells tested, our results suggest an almost ubiquitous expression of the NR in the different cell lineages of the immune system. The expression of CAR, CoupTFalpha, FXR was also confirmed at a protein level and despite conspicuous mRNA levels of HNF4alpha, only low levels of this receptor were detectable in the nuclear fraction of PBMCs. Expression of the latter receptors was mostly only a fraction (4-20%) of their expression in the thyroid gland, the adrenal gland, the lung or subcutaneous adipose tissue. The Spearman rank order correlation test was performed to examine the correlation in expression between individual nuclear receptor pairs in the four cell types for several donors. Distinct correlation patterns were observed between receptor pairs in the individual cell types. In CD4 T cells four NR, GCNF, PPARgamma, PPARalpha7 and RevErbbeta are perfectly correlated with each other (P> or =0.0167). In the other cell types correlations between NR pairs were more diverse, but also statistically highly significant. Interestingly, the relative expression level of a number of receptor pairs ranked identical or similar in at least three (CoupTFalpha and PPARbeta/delta, CoupTFbeta and HNF4alpha as well as RORbeta and PXR) or four cell types (CoupTFalpha and CoupTFbeta, PPARgamma and RevErbbeta). Despite the variability of NR expression in immune cells, these results suggest that some of the NR may be co-regulated in human immune cells.

Female↗

Effects of transdermally administered nicotine on aspects of attention, task load, and mood in women and men.

This double-blind placebo-controlled study was conducted to determine nicotine effects on diverse types of attentional performance, task load, and mood considering sex effects as suggested by animal studies. Twelve smokers, 12 deprived smokers and 12 nonsmokers (6 females, 6 males in each group) were investigated. Participants were treated either by 5 mg/16 h nicotine patches (Nicorette) or placebo. Effects of treatment were examined by a computerized attention-test battery; mood was assessed by the Berliner-Alltagssprachliches-Stimmungs-Inventar and task load by the NASA Task Load Index (NASA-TLX). Results showed that nicotine significantly increased the number of hits and decreased reaction time (RT) in the vigilance task. In the selective attention task combined with irrelevant speech as background noise, nicotine enhanced rate of hits. Although it was indicated that nicotine leads to a generally higher accuracy in attention tasks, response time of visual search was prolonged, contradicting a universal facilitation by nicotine. Participants experienced mental demand and temporal demand lower and rated alertness higher when in the nicotine condition. These effects were independent of smoking status, indicating "true" nicotine effects. Females took significant advantage of nicotine in the vigilance task, reaching the performance level of males, accompanied by a higher rated alertness. Results indicate task- and sex-dependent nicotine effects.

Administration, Cutaneous↗

The effect of cell phone type on drivers subjective workload during concurrent driving and conversing.

The effect of three types of cell phones (hand held, hands free with an external speaker and personal hands free) on total subjective workload (including its constituent components; mental demand, physical demand, temporal demand, performance, effort and frustration) and intelligibility was measured using the NASA-task load index (TLX) and the modified rhyme test (MRT), respectively in 13 experienced drivers (nine male, four female, age range 28-65 years), whilst driving on a rural highway. The drivers rated all components of workload for each type of cell phone to be significantly higher than for a control condition in which no cell phone was used. The mean (standard deviation) total workload was lowest for the personal hands free cell phone (7.1(3.65)) and highest for the hands free speaker phone (10.8 (3.63)) (P<0.001). The mean (standard deviation) intelligibility score was highest for the personal hands free cell phone (74.1 (7.9)) and lowest for the hands free speaker phone (55.0 (10.4)) (P<0.001). Frustration was significantly correlated with total workload (0.60, P<0.001) and intelligibility was significantly correlated with frustration (-0.35, P<0.05). Physical demand was not a high contributor to total workload. It is concluded that a personal hands free cell phone would interfere least with the cognitive demands of driving.

Adult↗

Fierce: a new mouse deletion of Nr2e1; violent behaviour and ocular abnormalities are background-dependent.

A new spontaneous mouse mutation named fierce (frc) is deleted for the nuclear receptor Nr2e1 gene (also known as Tlx, mouse homolog of Drosophila tailless). The fierce mutation is genetically and phenotypically similar to Nr2e1 targeted mutations previously studied on segregating genetic backgrounds. However, we have characterized the fierce brain, eye, and behavioural phenotypes on three defined genetic backgrounds (C57BL/6J, 129P3/JEms, and B6129F1). The data revealed many novel and background-dependent phenotypic characteristics. Whereas abnormalities in brain development, hypoplasia of cerebrum and olfactory lobes, were consistent on all three backgrounds, our novel finding of enlarged ventricles in 100% and overt hydrocephalus in up to 30% of fierce mice were unique to the C57BL/6J background. Developmental eye abnormalities were also background-dependent with B6129F1-frc mice having less severe thinning of optic layers and less affected electroretinogram responses. Impaired regression of hyaloid vessels was observed in all backgrounds. Furthermore, retinal vessels were deficient in size and number in 129P3/JEms-frc and B6129F1-frc mice but almost entirely absent in C57BL/6J-frc mice. We present the first standardized behavioural tests conducted on Nr2e1 mutant mice and show that C57BL/6J-frc and B6129F1-frc mice have deficits in sensorimotor assays and are hyperaggressive in both sexes and backgrounds. However, C57BL/6J-frc mice were significantly more aggressive than B6129F1-frc mice. Overall, this extensive characterization of the fierce mutation is essential to its application for the study of behavioural, and brain and eye developmental disorders. In addition, the background-dependent differences revealed will enable the identification of important genetic modifiers.

Aggression↗

Early steps in the evolution of multicellularity: deep structural and functional homologies among homeobox genes in sponges and higher metazoans.

The sponge homeobox gene EmH-3 had not been attributed to any homeobox family. Comparative promoter and homeodomain sequence analyses suggest that it is related to the Hox11 gene, which belongs to the Tlx homeobox family. Hox11 is highly expressed in proliferating progenitor cells, but expression is downregulated during cell differentiation. Using reporter gene methodology, we monitored function of the sponge EmH-3 promoter transfected into human erythroleukemia K562 cells. These cells express the Tlx/Hox11 gene constitutively, and downregulate its expression upon differentiation. The same pattern of expression and downregulation was observed for the sponge reporter construct. We propose that Tlx/Hox11 genes have structural and functional homologies conserved in phylogenetically distant groups, that represent a deep homology in the regulation of cell proliferation, commitment and differentiation.

Amino Acid Sequence↗

Evidence for 14 homeobox gene clusters in human genome ancestry.

The arrangement of Hox genes into physical clusters is fundamental to the patterning of animal body plans. Other homeobox genes are often described as dispersed, with only occasional examples of linkage reported, such as the amphioxus ParaHox and Drosophila 93D/E clusters. This clustering is unlikely to be the derived condition, as the genes of the ParaHox and 93D/E clusters are phylogenetically widespread. To assess whether clustering is retained in mammals, and to infer its history, we considered the distribution of ANTP superclass homeobox genes in human and mouse genomes. We postulate four ancient arrays of ANTP superclass genes in animal genomes, denoted 'extended Hox' (Hox, Evx and Mox), NKL (including NK1, NK3, NK4, Lbx, Tlx, Emx, Vax, Hmx, NK6, Msx), ParaHox (Cdx, Xlox, Gsx) and EHGbox (En, HB9, Gbx). Each of these duplicated in the ancestry of the human genome to yield four Hox, four NKL, four ParaHox and at least two EHGbox clusters or arrays. Two of the human NKL clusters (four in mouse) have subsequently been split by chromosome rearrangement, as has one human EHGbox array. We date all cluster duplications to early chordate evolution and infer that three clusters (Hox, NKL, EHGbox) resided on the same chromosome before duplication.

Animals↗

Luminescent amidate-bridged one-dimensional platinum(II)-thallium(I) coordination polymers assembled via metallophilic attraction.

The neutral square-planar complexes [Pt(RNH2)2(NHCO(t)Bu)2] (R = H, 1; Et, 2) and [Pt(DACH)(NHCO(t)Bu)2] (DACH = 1,2-diaminocyclohexane, 3) act as metalloligands and make bonds to closed-shell Tl(I) ions to afford one- and two-dimensional platinum-thallium oligomers or polymers based on heterobimetallic backbones. A series of heteronuclear platinum(II)-thallium(I) complexes have been synthesized and structurally characterized. The structures of the Pt-Tl compounds resulted from [Pt(RNH2)2(NHCO(t)Bu)2] and TlX [X = NO3(-), ClO4(-), PF6(-), and Cp2Fe(CO2)2(2-)] are dependent on both counteranions and the amine substituents. The compounds [Pt(NH3)2(NHCO(t)Bu)2Tl]X (X = NO3(-), 8; ClO4(-), 9) adopt one-dimensional zigzag chain structures consisting of repeatedly stacked [Pt(NH3)2(NHCO(t)Bu)2Tl]+ units, whereas [{Pt(NH3)2(NHCO(t)Bu)2}2Tl2]X2 (X = PF6(-), 10) consists of a helical chain. Compound 3 reacts with Tl+ to give [{Pt(DACH)(NHCO(t)Bu)2}2Tl](NO3) x [Pt(DACH)(NHCO(t)Bu)2] x 3 H2O (14) and one-dimensional polymeric [{Pt(DACH)(NHCO(t)Bu)2}2Tl2]X2 (X = ClO4(-), 15; PF6(-), 16). Reactions of [Pt(DACH)(NHCOCH3)2] with Tl+ ions afford one-dimensional coordination polymers [{Pt(DACH)(NHCOCH3)2}2Tl2]X2 (X = NO3(-), 17; ClO4(-), 18; PF6(-), 19). The polymeric [{Pt(DACH)(NHCOR')2}2Tl2]2+ (R = CH3, (t)Bu) complexes adopt helical structures, which are generated around the crystallographic 2(1) screw axis. The distance between the coils corresponds to the unit cell length, which ranges from 22.58 to 22.68 A. The platinum-thallium bond distances fall in a narrow range around 3.0 A. The complexes derived from [Pt(NH3)2(NHCO(t)Bu)2] are luminescent at 77 K. The trinuclear complexes [{Pt(RNH2)(NHCO(t)Bu)2}2Tl]+ do not emit at room temperature but are emissive at 77 K, whereas the polymeric platinum-thallium complexes containing 1,2-diaminocyclohexane are intensively luminescent at both room temperature and 77 K. The color variations are interesting; 15 exhibits intense yellow-green, 16 exhibits green, and 17-19 exhibit blue luminescence. The presence of bonding between platinum and thallium is supported by the short metal-metal separations and the strong low-energy luminescence of these compounds in their solid states.

Crystallography, X-Ray↗